Inkjet recording yellow ink, inkjet recording ink set and inkjet recording method

ABSTRACT

Disclosed is an inkjet recording yellow ink comprising at least one water-soluble azo dye selected from the group consisting of a compound represented by formula (Y) described below and a salt thereof and at least one glycol ether represented by formula (A) described below, wherein the glycol ether is contained in an amount of 25% by mass to 100% by mass relative to a total amount of water-soluble organic solvent in the ink.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2008-245022 filed on Sep. 24, 2008, thedisclosures of which is incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an inkjet recording yellow ink suitablefor recording an image by ejecting an ink according to an inkjetrecording method. Further, it relates to an inkjet recording ink set andan inkjet recording method each using the same.

2. Description of the Related Art

As an inkjet recording ink, a water-based ink, an oil-based ink, or asolid (fusion type) ink is used.

A dye used in the inkjet recording inkjet is typically required to havethe following properties: good solubility with respect to a solvent suchas water; good hue; fastness with respect to light, heat and activatedgas in the atmosphere (for example, oxidizing gas such as NOx or ozone,as well as SOx and so on); excellent resistance to water or chemicals;good fixing property with respect to an image-receiving material, andresultantly less bleeding; excellent storage stability in an ink; andhigh color purity.

It is especially important that the dye has fastness with respect tolight, moisture, and heat. In consideration of properties of thematerial for recording, for example, it is desired that when an image isrecorded on an ink-receiving layer containing white inorganic porousparticles, the recorded image has fastness with respect to oxidizing gassuch as ozone in the atmosphere.

Generally, when a color image is recorded using colors such as yellow,magenta and cyan, an image with an excellent coloration is obtained byregulating a color balance at the time of recording. However, if thedegrees of fading of the respective colors different from each otherunder the same environmental conditions with the lapse of time afterrecording, imbalance in color gradually arises with the lapse of time,which leads to a seriously deteriorated color tone of an entire image.

With respect to fastness of the color, as an ink that allows recordingof an image having fastness, an ink composition having fastness withrespect to light, heat, moisture and activated gas in the atmosphere hasbeen disclosed (see, for example, JP-A-No. 2007-197491).

Further, an ink composition containing a colorant including a particularyellow dye, a glycol ether having an HLB value of 5.4 to 8.0, and asolvent has been disclosed (see, for example, JP-A-No. 2007-302810). Inthis related art, it is described that when the above-mentioned yellowink composition is used in an ink set that is composed of the yellow inkcomposition and ink compositions other than the yellow ink compositionin combination, a uniform color mixing and resultantly a fine colorationwithout color unevenness can be achieved, and the coloration state canbe maintained over a long period of time.

However, in the aforementioned previous ink compositions, because theyellow dye is especially excellent in fastness compared to cyan dye ormagenta dye, sometimes color imbalance in the image tends to occur withthe lapse of time after recording, and the color tone of the image atthe time of recording cannot be stably maintained for a long time.

Further, in previous ink compositions containing a yellow dye and aglycol ether, many dyes that exhibit a low fastness at an initial stagefade, and change in density at an initial stage is large. Further, achange of hue owing to fading is so remarkable that an image of adesired color tone cannot be stably maintained.

SUMMARY OF THE INVENTION

The invention has been made in consideration of the above-mentionedproblems. Accordingly, an object of the invention is to provide aninkjet recording yellow ink and an inkjet recording ink set, each ofwhich is capable of stably keeping a color balance of an image for along period of time and thereby capable of recording an image with anexcellent storage stability, and an inkjet recording method using theyellow ink or the ink set.

The present inventors have found that among many organic solvents,monoalkylene or dialkylene glycol ether especially leads to lessreduction in color density of dye, and that when a color tone isregulated by reducing an amount of a yellow dye, a desired density andhue can be maintained and thereby fading balance with the lapse of timecan be effectively achieved. The invention has been completed on thebasis of the aforementioned findings.

The above object of the invention has been attained by the followingmeans.

<1> An inkjet recording yellow ink comprising at least one water-solubleazo dye selected from the group consisting of a compound represented byformula (Y) described below and a salt thereof and at least one glycolether represented by formula (A) described below, wherein the glycolether is contained in an amount of 25% by mass to 100% by mass relativeto a total amount of water-soluble organic solvent in the ink.

<2> The inkjet recording yellow ink described in the preceding <1>,wherein the glycol ether has an HLB value by the Davis method of 7.0 to9.5.

<3> The inkjet recording yellow ink described in the preceding <1> or<2>, wherein the compound represented by formula (Y) is selected fromthe group consisting of a compound represented by formula (Y-1)described below, a compound represented by formula (Y-2) describedbelow, a compound represented by formula (Y-3) described below, acompound represented by formula (Y-4) described below, a compoundrepresented by formula (Y-5) described below, and a salt of any one ofthese compounds.

<4> The inkjet recording yellow ink described in any one of thepreceding <1> to <3>, wherein the glycol ether has an HLB value by theDavis method of 8.1 to 9.1.

<5> The inkjet recording yellow ink described in any one of thepreceding <1> to <4>, wherein the glycol ether is at least one compoundselected from the group consisting of diethylene glycol monopropylether,diethylene glycol monoethylether, ethylene glycol monoethylether,diethylene glycol monomethylether, ethylene glycol monomethylether,dipropylene glycol monomethylether, and propylene glycolmonomethylether.

<6> The inkjet recording yellow ink described in any one of thepreceding <1> to <5>, further comprising a nonionic surfactant.

<7> The inkjet recording yellow ink described in the preceding <6>,wherein the nonionic surfactant is an acetylene diol-series nonionicsurfactant.

<8> An inkjet recording ink set comprising the inkjet recording yellowink described in any one of the preceding <1> to <7>, a magenta inkcontaining a magenta dye and a cyan ink containing a cyan dye.

<9> The inkjet recording ink set described in the preceding <8>, whereinthe cyan dye is a water-soluble phthalocyanine dye selected from thegroup consisting of a compound represented by formula (C-1) describedbelow and a salt thereof.

<10> The inkjet recording ink set described in the preceding <8> or <9>,wherein the magenta ink contains a water-soluble azo dye represented byformula (M-1) described below.

<11> The inkjet recording ink set described in any one of the preceding<8> to <10>, further comprising a black ink.

<12> The inkjet recording ink set described in the preceding <11>,wherein the black ink contains a water-soluble azo dye represented byformula (B-1) described below.

<13> A inkjet recording method for recording an image on an inkjetrecording medium having an ink-receiving layer containing inorganicporous fine white pigment particles on a support, the method comprising:using the inkjet recording yellow ink described in any one of thepreceding <1> to <7>, or the inkjet recording ink set described in anyone of the preceding <8> to <12>.

<14> The inkjet recording method described in the preceding <13>,wherein the ink receiving layer contains polyvinyl alcohol orderivatives thereof as a binder.

According to the invention, it is possible to provide an inkjetrecording yellow ink and an inkjet recording ink set, each of which iscapable of keeping a color balance of the image stably for a long periodof time and thereby capable of recording an image with an excellentstorage stability, and an inkjet recording method using the yellow inkor the ink set.

DETAILED DESCRIPTION OF THE INVENTION

The inkjet recording yellow ink, an inkjet recording ink set, and aninkjet recording method using the yellow ink or the ink set of theinvention are explained in detail below.

<Inkjet Recording Yellow Ink>

The inkjet recording yellow ink of the invention (hereinafter, sometimesreferred to simply as “yellow ink”) contains, as essential components,at least one water-soluble azo dye selected from the group consisting ofa compound represented by formula (Y) described below and a salt thereofand at least one glycol ether (hereinafter, sometimes referred to as“glycol ether used in the invention”) represented by formula (A)described below. Further, the inkjet recording yellow ink has acomposition in which the glycol ether is contained in an amount of 25%by mass to 100% by mass relative to a total amount of water-solubleorganic solvent in the ink.

It is preferable that the yellow ink of the invention further contains anonionic surfactant. If necessary, the yellow ink may also containsother water-soluble organic solvent excluding the glycol ether used inthe invention, and/or water, or other components.

In the invention, monoalkylene or dialkylene glycol alkylether is usedas a water-soluble organic solvent together with a pyrazole azo-seriesyellow dye which is used as a yellow coloring dye, and thereby, even ifa content of the yellow dye is reduced, or an amount of the organicsolvent is increased, both density and hue of the yellow color can bemaintained, and a color balance of a multi-color image during fadingwith the lapse of time can be maintained stably with no substantialchange from the color balance at an initial stage after recording.According to the invention, it is possible to obtain an image having agood color balance and an excellent storage stability for a long time.

[Water-Soluble Azo Dye (Yellow Series)]

The yellow ink of the invention contains, as a dye, at least onewater-soluble azo dye selected from the group consisting of a compoundrepresented by formula (Y) described below and a salt thereof. Thewater-soluble azo dye is excellent in both color reproduction andfastness with respect to light, heat, moisture and activated gas in theatmosphere. Herein, the term “water-soluble” means that the azo dye isdissolved in water at a percentage of 1 g or more relative to 100 g (25°C.) of water.

wherein in formula (Y), G represents a heterocyclic group; R, X, Y, Z,and Q each independently represent a monovalent, divalent, or trivalentgroup; n represents an integer of 1 to 3; when n is 1, R, X, Y, Z, Q andG each independently represent a monovalent group; when n is 2, R, X, Y,Z, Q and G each independently represent a monovalent or divalent group,and at least one of them represents a divalent substituent; and when nis 3, R, X, Y, Z, Q and G each independently represent a monovalent,divalent, or trivalent group, and at least two of them represent adivalent substituent, or at least one of them represents a trivalentsubstituent.

The formula (Y) is explained in detail below.

In formula (Y), G is preferably a 5- to 8-membered heterocyclic group.Among these rings, 5- or 6-membered substituted, or unsubstitutedaromatic or non-aromatic heterocyclic groups, which may be condensed,are preferable. Further, 5- or 6-membered aromatic heterocyclic groupshaving 3 to 30 carbon atoms are more preferable.

Examples of the heterocyclic group represented by the G are describedbelow without specifying a substitution cite of the ring:

pyridine, pyrazine, pyridazine, pyrimidine, triazine, quinoline,isoquinoline, quinazoline, cinnoline, phthalazine, quinoxaline, pyrrol,indole, furan, benzofuran, thiophene, benzothiophene, pyrazole,imidazole, benzimidazole, triazole, oxazole, benzoxazole, thiazole,benzothiazole, isothiazole, benzoisothiazole, thiadiazole, isooxazole,benzoisooxazole, pyrrolidine, piperidine, piperazine, imidazolidine,thiazoline, and sulfolane.

If the heterocyclic group is able to have a substituent, further theheterocyclic group may have the following substituent.

Examples of the substituent include a straight chain or branched chainalkyl group having 1 to 12 carbon atoms, a straight chain or branchedchain aralkyl group having 7 to 18 carbon atoms, a straight chain orbranched chain alkenyl group having 2 to 12 carbon atoms, a straightchain or branched chain alkynyl group having 2 to 12 carbon atoms, astraight chain or branched chain cycloalkyl group having 3 to 12 carbonatoms, a straight chain or branched chain cycloalkenyl group having 3 to12 carbon atoms (among the aforementioned groups, each of the groupshaving a branched chain is preferable from a reason of improvement inboth solubility of dye and storage stability of ink. Groups having anasymmetric carbon atom are especially preferable. For example, methyl,ethyl, isopropy, sec-butyl, t-butyl, 2-ethylhexyl,2-methylsulfonylethyl, 3-phenoxypropyl, trifluoromethyl, and cyclopentylgroups are exemplified.), a halogen atom (for example, chlorine,bromine), an aryl group (for example, phenyl, 4-t-butylphenyl,2,4-di-t-amylphenyl), a heterocyclic group (for example, imidazolyl,pyrazolyl, triazolyl, 2-furyl, 2-thienyl, 2-pyrimidinyl,2-benzothizolyl), a cyano group, a hydroxyl group, a nitro group, acarboxyl group, an amino group, an alkyloxy group (for example, methoxy,ethoxy, 2-methoxyethoxy, 2-methylsulfonylethoxy), an aryloxy group (forexample, phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy,3-t-butyloxycarbonylphenoxy, 3-methoxycarbonylphenoxy), an acylaminogroup (for example, acetoamido, benzoamido,4-(3-t-butyl-4-hydroxyphenoxy)butane amido), an alkylamino group (forexample, methylamino, butylamino, diethylamino, methylbutylamino), anarylamino group (for example, phenylamino, 2-chloroanilino), an ureidogroup (for example, phenylureido, methylureido, N,N-dibutylureido), asulfamoylamino group (for example, N,N-dipropylsulfamoylamino), analkylthio group (for example, methylthio, octylthio,2-phenoxyethylthio), an arylthio group (for example, phenylthio,2-butoxy-5-t-octyl phenylthio, 2-carboxylphenylthio), analkyloxycarbonylamino group (for example, methoxycarbonylamino), analkylsulfonylamino group and an arylsulfonylamino group (for example,methylsulfonylamino, phenylsulfonylamino, p-toluenesulfonylamino), acarbamoyl group (for example, N-ethylcarbamoyl, N,N-dibutylcarbamoyl), asulfamoyl group (for example, N-ethylsulfamoyl, N,N-dipropylsulfamoyl,N-phenylsulfamoyl), a sulfonyl group (for example, methylsulfonyl,octylsulfonyl, phenylsulfonyl, p-toluenesulfonyl), an alkyloxycarbonylgroup (for example, methoxycarbonyl, butoxycarbonyl), a heterocyclic oxygroup (for example, 1-phenyltetrazole-5-oxy, 2-tetrahydropyranyloxy), anazo group (for example, phenylazo, 4-methoxyphenylazo,4-pivaroylaminophenylazo, 2-hydroxy-4-propanoylphenylazo), an acyloxygroup (for example, acetoxy), a carbamoyloxy group (for example,N-methylcarbamoyloxy, N-phenylcarbamoyloxy), a silyloxy group (forexample, trimethylsilyloxy, dibutylmethylsilyloxy), anaryloxycarbonylamino group (for example, phnoxycarbonylamino), an imidogroup (for example, N-succinimido, N-phthalimido), a heterocyclic thiogroup (for example, 2-benzothiazolylthio,2,4-diphenoxy-1,3,5-triazole-6-thio, 2-pyridylthio), a sulfinyl group(for example, 3-phenoxypropylsulfinyl), a phosphonyl group (for example,phenoxyphosphonyl, octyloxyphosphonyl, phenylphosphonyl), anaryloxycarbonyl group (for example, phenoxycarbonyl), an acyl group (forexample, acetyl, 3-phenylpropanoyl, benzoyl), or ionic hydrophilic group(for example, carboxyl, sulfo, phosphono, quaterary ammonium).

In the above-described formula (Y), preferable examples of Q, R, X, Yand Z are explained in detail below.

When Q, R, X, Y, and Z represent a monovalent group, the monovalentgroup represents a hydrogen atom, or a monovalent substituent. Themonovalent substituent is detailed below. Examples of the monovalentsubstituent include a halogen atom, an alkyl group, a cycloalkyl group,an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, aheterocyclic group, a cyano group, a hydroxyl group, a nitro group, analkoxy group, an aryloxy group, a silyloxy group, a heterocyclic oxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group; an amino group which may be analkylamino group, or an aryamino group; an acylamino group (amido), anaminocarbonylamino group (ureido), an alkoxycarbonylamino group, anaryloxycarbonylamino group, a sulfamoylamino group, analkylsulfonylamino group, an arylsulfonylamino group, an alkylthiogroup, an arylthio group, a heterocyclic thio group, a sulfamoyl group,an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group,an arylsulfonyl group, an acyl group, an aryloxycarbonyl group, analkoxycarbonyl group, a carbamoyl group, a phosphino group, a phosphinylgroup, a phosphinyloxy group, a phosphinylamino group, a silyl group, anazo group, or an imido group. Further, each of the above groups may havea substituent.

Of the monovalent group, a hydrogen atom, a halogen atom, an alkylgroup, an aryl group, a heterocyclic group, a cyano group, an alkoxygroup, an amido group, an ureido group, an alkylsulfonylamino group, anarylsulfonylamino group, a sulfamoyl group, an alkylsulfonyl group, anarylsulfonyl group, a carbamoyl group, or an alkoxycarbonyl group ispreferable in consideration of a good storage stability with respect tomoisture, oxidizing gas, light, and the like of the recorded image, andan excellent hue. Furthermore, a hydrogen atom, a halogen atom, an alkylgroup, an aryl group, a cyano group, an alkylsulfonyl group, anarylsulfonyl group, or a heterocyclic group is preferable. Among thesegroups, a hydrogen atom, an alkyl group, an aryl group, a cyano group,or an alkylsulfonyl group is still furthermore preferable.

The above-described Q, R, X, Y, and Z are explained in more detailbelow.

The halogen atom represented by Q, R, X, Y, and Z represents a chlorineatom, a bromine atom, or an iodine atom. Of these atoms, a chlorineatom, or a bromine atom is preferable. A chlorine atom is furthermorepreferable.

The alkyl group represented by Q, R, X, Y, and Z encompasses asubstituted alkyl group and an unsubstituted alkyl group. Thesubstituted alkyl group or unsubstituted alkyl group preferably has from1 to 30 carbon atoms. Examples of the substituent include the sameexamples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Among these examples, ahydroxyl group, an alkoxy group, a cyano group, a halogen atom, a sulfogroup or a salt thereof, or a carboxyl group or a salt thereof ispreferable. Specific examples of the alkyl group include a methyl group,an ethyl group, a butyl group, a t-butyl group, n-octyl group, aneicosyl group, a 2-chloroethyl group, a hydroxyethyl group, a cyanoethylgroup, and a 4-sulfobutyl group.

The cycloalkyl group represented by Q, R, X, Y, and Z encompasses asubstituted or unsubstituted cycloalkyl group. The substituted orunsubstituted cycloalkyl group preferably has from 5 to 30 carbon atoms.Examples of the substituent include the same examples of the substituentas recited in the case where the aforementioned G optionally has asubstituent. Specific examples of the cycloalkyl group include acyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexylgroup.

The aralkyl group represented by Q, R, X, Y, and Z encompasses asubstituted or unsubstituted aralkyl group. The substituted orunsubstituted aralkyl group preferably has from 7 to 30 carbon atoms.Examples of the substituent include the same examples of the substituentas recited in the case where the aforementioned G optionally has asubstituent. Specific examples of the aralkyl group include a benzylgroup, and a 2-phenetyl group.

The alkenyl group represented by Q, R, X, Y and Z represents asubstituted or unsubstituted straight chain, branched, or cyclic alkenylgroup. The alkenyl group is a substituted or unsubstituted alkenyl grouppreferably having 2 to 30 carbon atoms. Specific examples of the alkenylgroup include a vinyl group, an allyl group, a prenyl group, a geranylgroup, an oleyl group, a 2-cyclopentene-1-yl group, and a2-cyclohexene-1-yl group.

The alkynyl group represented by Q, R, X, Y, and Z is a substituted orunsubstituted alkynyl group preferably having 2 to 30 carbon atoms.Specific examples of the alkynyl group include an ethynyl group and apropargyl group.

The aryl group represented by Q, R, X, Y, and Z is a substituted orunsubstituted aryl group preferably having 6 to 30 carbon atoms.Specific examples of the aryl group include a phenyl group, a p-torylgroup, a naphthyl group, a m-chlorophenyl group, and ao-hexadecanoylaminophenyl group. Examples of the substituent include thesame examples of the substituent as recited in the case where theaforementioned G optionally has a substituent.

The heterocyclic group represented by Q, R, X, Y, and Z is preferably amonovalent group derived from a substituted or unsubstituted 5- or6-membered atomatic or nonaromatic hetero ring compound from which onehydrogen atom is removed. Further, the hetero ring may be condensed. Theheterocyclic group is more preferably a 5- or 6-membered atomaticheterocyclic group having 3 to 30 carbon atoms. Examples of thesubstituent include the same examples of the substituent as recited inthe case where the aforementioned G optionally has a substituent.Specific examples of the heterocyclic group are recited below withoutspecifying the substitution site of the hetero ring:

pyridine, pyrazine, pyridazine, pyrimidine, triazine, quinoline,isoquinoline, quinazoline, cinnoline, phthalazine, quinoxaline, pyrrole,indole, furan, benzofuran, thiophene, benzothiophene, pyrazole,imidazole, benzimidazole, triazole, oxazole, benzoxazole, thiazole,benzothiazole, isothiazole, benzoisothiazole, thiadiazole, isoxazole,benzisoxazole, pyrrolidine, piperidine, piperazine, imidazolidine, andthiazoline.

The alkoxy group represented by Q, R, X, Y, and Z encompasses asubstituted or unsubstituted alkoxy group. The substituted orunsubstituted alkoxy group preferably has from 1 to 30 carbon atoms.Examples of the substituent include the same examples of the substituentas recited in the case where the aforementioned G optionally has asubstituent. Specific examples of the alkoxy group include a methoxygroup, an ethoxy group, a isopropoxy group, a n-octyloxy group, amethoxyethoxy group, a hydroxyethoxy group, and a 3-carboxypropoxygroup.

The aryloxy group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted aryloxy group having from 6 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the aryloxy group include aphenoxy group, a 2-methylphenoxy group, a 4-t-butylphenoxy group, a3-nitrophenoxy group, and a 2-tetradecanoylaminophenoxy group.

The silyloxy group represented by Q, R, X, Y, and Z is preferably asilyloxy group having from 3 to 20 carbon atoms. Specific examples ofthe silyloxy group include a trimethylsilyloxy group, and at-butyldimethylsilyloxy group.

The heterocyclic oxy group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted heterocyclic oxy group havingfrom 2 to 30 carbon atoms. Examples of the substituent include the sameexamples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of theheterocyclic oxy group include a 1-phenyltetrazole-5-oxy, and2-tetrahydropyranyloxy group.

The acyloxy group represented by Q, R, X, Y, and Z is preferably aformyloxy group, a substituted or unsubstituted alkyl carbonyloxy grouphaving from 2 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonyloxy group having from 6 to 30 carbon atoms. Examples of thesubstituent include the same examples of the substituent as recited inthe case where the aforementioned G optionally has a substituent.Specific examples of the acyloxy group includean a formyloxy group, anacetyloxy group, a pivaloyloxy group, a stearoyloxy group, a benzoyloxygroup, and a p-methoxyphenylcabonyloxy group.

The carbamoyloxy group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted carbamoyloxy group having from 1 to 30carbon atoms. Examples of the substituent include the same examples ofthe substituent as recited in the case where the aforementioned Goptionally has a substituent. Specific examples of the carbamoyloxygroup include an N,N-dimethylcarbamoyloxy group, anN,N-diethylcarbamoyloxy group, a morpholinocarbonyloxy group, anN,N-di-n-octylaminocarbonyloxy group, and an N-n-octylcarbamoyloxygroup.

The alkoxycarbonyloxy group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted alkoxycarbonyloxy group havingfrom 2 to 30 carbon atoms. Examples of the substituent include the sameexamples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of thealkoxycarbonyloxy group include a methoxycarbonyloxy group, anethoxycarbonyloxy group, a t-butoxycarbonyloxy group, and ann-octylcarbonyloxy group.

The aryloxycarbonyloxy group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted aryloxycarbonyloxy grouphaving from 7 to 30 carbon atoms. Examples of the substituent includethe same examples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of thearyloxycarbonyloxy group include a phenoxycarbonyloxy group, a p-methoxyphenoxycarbonyloxy group, and a p-n-hexadecyloxyphenoxycarbonyloxygroup.

The amino group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted alkylamino group having from 1 to 30 carbonatoms, and a substituted or unsubstituted arylamino group having from 6to 30 carbon atoms. Examples of the substituent include the sameexamples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of theamino group include an amino group, a methylamino group, a dimethylaminogroup, an anilino group, an N-methylanilino group, a diphenylaminogroup, a hydroxyethylamino group, a carboxyethylamino group, asulfoethylamino group, and a 3,5-dicarboxyanilino group.

The acylamino group represented by Q, R, X, Y, and Z is preferably aformylamino group, a substituted or unsubstituted alkylcarbonylaminogroup having from 1 to 30 carbon atoms, and a substituted orunsubstituted arylcarbonylamino group having from 6 to 30 carbon atoms.Examples of the substituent include the same examples of the substituentas recited in the case where the aforementioned G optionally has asubstituent. Specific examples of the acylamino group include aformylamino group, an acetylamino group, a pivaloylamino group, alauroylamino group, a benzoylamino group, and a3,4,5-tri-n-octyloxyphenylcarbonylamino group.

The aminocarbonylamino group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted aminocarbonylamino grouphaving from 1 to 30 carbon atoms. Examples of the substituent includethe same examples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of theaminocarbonylamino group include a carbamoylamino group, anN,N-diethylamino carbonylamino group, and a morpholinocarbonylaminogroup.

The alkoxycarbonylamino group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted alkoxycarbonylamino grouphaving from 2 to 30 carbon atoms. Examples of the substituent includethe same examples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of thealkoxycarbonylamino group include a methoxycarbonylamino group, anethoxycarbonylamino group, a t-butoxycarbonylamino group, ann-octadecyloxycarbonylamino group, and a N-methyl-methoxycarbonylaminogroup.

The aryloxycarbonylamino group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted aryloxycarbonylamino grouphaving from 7 to 30 carbon atoms. Examples of the substituent includethe same examples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of thearyloxycarbonylamino group include a phenoxycarbonylamino group, ap-chlorophenoxy carbonylamino group, and am-n-octyloxyphenoxycarbonylamino group.

The sulfamoylamino group represented by Q, R, X, Y, and Z is preferablya substituted or unsubstituted sulfamoylamino group having from 0 to 30carbon atoms. Examples of the substituent include the same examples ofthe substituent as recited in the case where the aforementioned Goptionally has a substituent. Specific examples of the sulfamoylaminogroup include a sulfamoylamino group, an N,N-dimethylaminosulfonyl aminogroup, and an N-n-octylaminosulfonylamino group.

The alkyl or aryl sulfonylamino group represented by Q, R, X, Y, and Zis preferably a substituted or unsubstituted alkylsulfonylamino grouphaving from 1 to 30 carbon atoms and a substituted or unsubstitutedarylsulfonylamino group having from 6 to 30 carbon atoms. Examples ofthe substituent include the same examples of the substituent as recitedin the case where the aforementioned G optionally has a substituent.Specific examples of the alkyl or arylsulfonylamino group include amethylsulfonylamino group, a butylsulfonylamino group, aphenylsulfonylamino group, a 2,3,5-trichlorophenylsulfonylamino group,and a p-methyl phenylsulfonylamino group.

The alkylthio group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted alkylthio group having from 1 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the alkylthio group include amethylthio group, an ethylthio group, and a n-hexadecylthio group.

The arylthio group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted arylthio group having from 6 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the arylthio group include aphenylthio group, a p-chlorophenylthio group, and an m-methoxyphenylthiogroup.

The heterocyclic thio group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted heterocyclic thio group havingfrom 2 to 30 carbon atoms. Examples of the substituent include the sameexamples of the substituent as recited in the case where theaforementioned G optionally has a substituent. Specific examples of theheterocyclic thio group include a 2-benzothiazolylthio group, and a1-phenyltetrazole-5-ylthio group.

The sulfamoyl group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted sulfamoyl group having from 0 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the sulfamoyl group include anN-ethylsulfamoyl group, an N-(3-dodecyloxypropyl) sulfamoyl group, a N,N-dimethyl sulfamoyl and an N-acetylsulfamoyl group, aN-benzoylsulfamoyl group, and a N—(N′-phenylcarbamoyl) sulfamoyl group.

The alkyl or aryl sulfinyl group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted alkylsulfinyl group havingfrom 1 to 30 carbon atoms, or a substituted or unsubstitutedarylsulfinyl group having from 6 to 30 carbon atoms. Examples of thesubstituent include the same examples of the substituent as recited inthe case where the aforementioned G optionally has a substituent.Specific examples of the alkyl or aryl sulfinyl group include amethylsulfinyl group, an ethylsulfinyl group, a phenylsulfinyl group,and a p-methlphenylsulfinyl group.

The alkyl or aryl sulfonyl group represented by Q, R, X, Y, and Z ispreferably a substituted or unsubstituted alkylsulfonyl group havingfrom 1 to 30 carbon atoms, or a substituted or unsubstitutedarylsulfonyl group having from 6 to 30 carbon atoms. Examples of thesubstituent include the same examples of the substituent as recited inthe case where the aforementioned G optionally has a substituent.Specific examples of the alkyl or aryl sulfonyl group include amethylsulfonyl group, an ethylsulfonyl group, a phenylsulfonyl group,and a p-toluene sulfonyl group.

The acyl group represented by Q, R, X, Y, and Z is preferably a formylgroup, a substituted or unsubstituted alkylcarbonyl group having from 2to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl grouphaving from 7 to 30 carbon atoms, or a substituted or unsubstitutedheterocyclic carbonyl group having from 4 to 30 carbon atoms wherein thecarbonyl group bonds to a carbon atom of the hetero ring. Examples ofthe substituent include the same examples of the substituent as recitedin the case where the aforementioned G optionally has a substituent.Specific examples of the acyl group include an acetyl group, a pivaloylgroup, a 2-chloroacetyl group, a stearoyl group, a benzoyl group, ap-n-octyloxyphenylcarbonyl group, a 2-pyridyl carbonyl group, and a2-furylcarbonyl group.

The aryloxycarbonyl group represented by Q, R, X, Y, and Z is preferablya substituted or unsubstituted aryloxycarbonyl group having from 7 to 30carbon atoms. Examples of the substituent include the same examples ofthe substituent as recited in the case where the aforementioned Goptionally has a substituent. Specific examples of the aryloxycarbonylgroup include a phenoxycarbonyl group, an o-chlorophenoxy carbonylgroup, a m-nitrophenoxycarbonyl group, and a p-t-butylphenoxycarbonylgroup.

The alkoxycarbonyl group represented by Q, R, X, Y, and Z is preferablya substituted or unsubstituted alkoxycarbonyl group having from 2 to 30carbon atoms. Examples of the substituent include the same examples ofthe substituent as recited in the case where the aforementioned Goptionally has a substituent. Specific examples of the alkoxycarbonylgroup include a methoxycarbonyl group, an ethoxycarbonyl group, at-butoxycarbonyl group, and an n-octadecyloxycarbonyl group.

The carbamoyl group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted carbamoyl group having from 1 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the carbamoyl group include acarbamoyl group, an N-methylcarbamoyl group, an N,N-dimethylcarbamoylgroup, an N,N-di-n-octylcarbamoy group, and an N-(methylsulfonyl)carbamoyl group.

The phosphino group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted phosphino group having from 2 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the phosphino group include adimethylphosphino group, a diphenylphosphino group, and amethylphenoxyphosphino group.

The phosphinyl group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted phosphinyl group having from 2 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the phosphinyl group include aphosphinyl group, a dioctyloxyphosphinyl group, and a diethoxyphosphinylgroup.

The phosphinyloxy group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted phosphinyloxy group having from 2 to 30carbon atoms. Examples of the substituent include the same examples ofthe substituent as recited in the case where the aforementioned Goptionally has a substituent. Specific examples of the phosphinyloxygroup include a diphenoxyphosphinyloxy group, and adioctyloxyphosphinyloxy group.

The phosphinylamino group represented by Q, R, X, Y, and Z is preferablya substituted or unsubstituted phosphinylamino group having from 2 to 30carbon atoms. Examples of the substituent include the same examples ofthe substituent as recited in the case where the aforementioned Goptionally has a substituent. Specific examples of the phosphinylaminogroup include a dimethoxyphosphinylamino group, and a dimethylaminophosphinylamino group.

The silyl group represented by Q, R, X, Y, and Z is preferably asubstituted or unsubstituted silyl group having from 3 to 30 carbonatoms. Examples of the substituent include the same examples of thesubstituent as recited in the case where the aforementioned G optionallyhas a substituent. Specific examples of the silyl group include atrimethylsilyl group, a t-butyldimethylsilyl group, and aphenyldimethylsilyl group.

Examples of the azo group represented by Q, R, X, Y, and Z include aphenylazo group, a 4-methoxyphenylazo group, a 4-pivaloylaminophenylazogroup, and a 2-hydroxy-4-propanoylphenylazo group.

Examples of the imino group represented by Q, R, X, Y, and Z include aN-succinimido group, and a N-phthalimido group.

When Q, R, X, Y and Z represent a divalent group, it is preferable thatthe divalent group is an alkylene group (for example, methylene,ethylene, propylene, butylene, pentylene), an alkenylene group (forexample, ethenylene, propenylene), an alkynylene group (for example,ethynylene, propynylene), an arylene group (for example, phenylene,naphthylene), a divalent heterocyclic group (for example,6-chloro-1,3,5-triazine-2,4-diyl, pyrimidine-2,4-diyl,pyrimidine-2,6-diyl, quinoxaline-2,3-diyl, pyridazine-3,6-diyl), —O—,—CO—, —NR′— wherein R′ represents a hydrogen atom, an alkyl group, or anaryl group, —S—, —SO₂—, —SO—, or a combination thereof (for example,—NHCH₂CH₂NH—, —NHCONH—).

Each of the alkylene group, an alkenylene group, the alkynylene group,the arylene group, the divalent heterocyclic group, and the alkyl group,or aryl group of R may have a substituent. Examples of the substituentinclude the same as those recited in the aforementioned G.

The alkyl group and the aryl group of R′ each have the same meanings asthose recited in the aforementioned G.

As the divalent group, an alkylene group having 10 or less carbon atoms,an alkenylene group having 10 or less carbon atoms, an alkynylene grouphaving 10 or less carbon atoms, an arylene group having 6 to 10 carbonatoms, a divalent heterocyclic group, —S—, —SO—, —SO₂—, or a combinationthereof (for example, —SCH₂CH₂S—, —SCH₂CH₂CH₂S—) are more preferable.

A total carbon atom number of the divalent connecting group ispreferably from 0 to 50, more preferably from 0 to 30, and furtherpreferably from 0 to 10.

When Q, R, X, Y, and Z represent a trivalent group, it is preferablethat the trivalent group is a trivalent hydrocarbon group, a trivalentheterocyclic group, >N—, or a combination with a divalent group (forexample, >NCH₂CH₂NH—, >NCONH—).

A total carbon atom number of the trivalent connecting group ispreferably from 0 to 50, more preferably from 0 to 30, and furtherpreferably from 0 to 10.

In formula (Y), n is preferably 1 or 2, and more preferably 2.

In formula (Y), a preferable example of the substituent represented by Xis an electron withdrawing group, especially having a Hammettsubstituent constant σ p of 0.20 or more, and more preferably 0.30 ormore. The upper limit of the σ p value of the electron withdrawing groupis preferably 1.0.

Specific examples of X, especially the electron withdrawing group havingthe a p value of 0.20 or more include an acyl group, an acyloxy group, acarbamoyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, acyano group, a nitro group, a dialkylphosphono group, a diarylphosphonogroup, a diarylphosphinyl group, an alkylsulfinyl group, an arylsulfinylgroup, an alkylsulfonyl group, an arylsulfonyl group, a sulfonyloxygroup, an acylthio group, a sulfamoyl group, a thiocyanate group, athiocarbonyl group, a halogenated alkyl group, a halogenated alkoxygroup, a halogenated aryloxy group, a halogenated alkylamino group, ahalogenated alkylthio group, an aryl group substituted with otherelectron withdrawing group(s) having the σ p value of 0.20 or more, aheterocyclic group, a halogen atom, an azo group, and a selenocyanategroup.

Preferable examples of X include an acyl group having 2 to 12 carbonatoms, an acyloxy group having 2 to 12 carbon atoms, a carbamoyl grouphaving 1 to 12 carbon atoms, an alkyloxycarbonyl group having 2 to 12carbon atoms, an aryloxycarbonyl group having 7 to 18 carbon atoms, acyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbonatoms, an arylsulfinyl group having 6 to 18 carbon atoms, analkylsulfonyl group having 1 to 12 carbon atoms, an arylsulfonyl grouphaving 6 to 18 carbon atoms, a sulfamoyl group having 0 to 12 carbonatoms, a halogenated alkyl group having 1 to 12 carbon atoms, ahalogenated alkoxy group having 1 to 12 carbon atoms, a halogenatedalkylthio group having 1 to 12 carbon atoms, a halogenated aryloxy grouphaving 7 to 18 carbon atoms, an aryl group having 7 to 18 carbon atomsand substituted with at least two other electron withdrawing groupshaving the σ p value of 0.20 or more, and a N, O, or S-containing 5 to8-membered heterocyclic group having 1 to 18 carbon atoms.

X is more preferably a cyano group, an alkylsulfonyl group having 1 to12 carbon atoms, an arylsulfonyl group having 6 to 18 carbon atoms, or asulfamoyl group having 0 to 12 carbon atoms.

X is further preferably a cyano group, an alkylsulfonyl group having 1to 12 carbon atoms, or a sulfamoyl group having 0 to 12 carbon atoms.Still further preferable X is a cyano group, or an alkylsulfonyl grouphaving 1 to 12 carbon atoms.

In formula (Y), preferable examples of Z include a hydrogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedcycloalkyl group, a substituted or unsubstituted alkenyl group, asubstituted or unsubstituted alkynyl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group.

Details of the group represented by Z are the same as those exemplifiedas the substituent on the heterocyclic group represented by G, andpreferable examples of Z are also the same as those of the substituenton the heterocyclic group.

Z is especially preferably a substituted aryl group, and a substitutedheterocyclic group, and furthermore preferably a substituted aryl group.

In formula (Y), Q is preferably a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted acyl group, asubstituted or unsubstituted alkylsulfonyl group, or a substituted orunsubstituted arylsulfonyl group, more preferably a hydrogen atom, asubstituted or unsubstituted alkyl group, or a substituted orunsubstituted acyl group, and furthermore preferably a hydrogen atom.

In formula (Y), R is preferably a substituted or unsubstituted alkylgroup having total carbon atoms 1 of 1 to 12, a substituted orunsubstituted aryl group having total carbon atoms of 6 to 18, or asubstituted or unsubstituted heterocyclic group having total carbonatoms of 4 to 12, more preferably a straight chain or branched alkylgroup having total carbon atoms of 1 to 8, furthermore preferably asecondary or tertiary alkyl group, and still further preferably at-butyl group.

In formula (Y), Y is preferably a hydrogen atom, a substituted orunsubstituted alkyl group having total carbon atoms of 1 to 12, asubstituted or unsubstituted aryl group having total carbon atoms of 6to 18, or a substituted or unsubstituted heterocyclic group having totalcarbon atoms of 4 to 12, more preferably a hydrogen atom, or a straightchain or branched alkyl group having total carbon atoms of 1 to 8,further preferably a hydrogen atom, or an alkyl group having totalcarbon atoms of 1 to 8, and still further preferably a hydrogen atom.

As a preferable combination of G, R, X, Y, Z and Q in the dyerepresented by formula (Y), compounds in which at least one of G, R, X,Y, Z and Q is an aforementioned preferable group are preferable, andcompounds in which two or more of G, R, X, Y, Z and Q are each anaforementioned preferable group are more preferable. Compounds in whichall of G, R, X, Y, Z and Q are aforementioned preferable groups are mostpreferable.

Especially preferable combinations of G, R, X, Y, Z and Q in the dyerepresented by formula (Y) include the following exemplary embodimentsof (i) to (vii):

(i) G is preferably a 5- to 8-membered nitrogen-containing hetero ring,more preferably a S-triazine, pyrimidine, pyridazine, pyrazine,pyridine, imidazole, pyrazole, or pyrrol ring, further preferably aS-triazine, pyrimidine, pyridazine, pyrazole, or pyrrol ring, and stillfurther preferably a S-triazine ring.

(ii) R is preferably a substituted or unsubstituted alkyl group havingtotal carbon atoms 1 of 1 to 12, a substituted or unsubstituted arylgroup having total carbon atoms of 6 to 18, or a substituted orunsubstituted heterocyclic group having total carbon atoms of 4 to 12,more preferably a straight chain or branched alkyl group having totalcarbon atoms of 1 to 8, further preferably a secondary or tertiary alkylgroup, and still further preferably a t-butyl group.

(iii) X is especially preferably a cyano group, an alkylsulfonyl grouphaving total carbon atoms of 1 to 12, an arylsulfonyl group having totalcarbon atoms of 6 to 18, or a sulfamoyl group having total carbon atomsof 0 to 12, further preferably a cyano group, or an alkylsulfonyl grouphaving total carbon atoms of 1 to 12, and still further preferably acyano group.

(iv) Y is preferably a hydrogen atom, a substituted or unsubstitutedalkyl group having total carbon atoms of 1 to 12, a substituted orunsubstituted aryl group having total carbon atoms of 6 to 18, or asubstituted or unsubstituted heterocyclic group having total carbonatoms of 4 to 12, more preferably a hydrogen atom, a straight chain orbranched alkyl group having total carbon atoms of 1 to 8, furtherpreferably a hydrogen atom, or an alkyl group having total carbon atomsof 1 to 8, and still further preferably a hydrogen atom.

(v) Z is preferably a hydrogen atom, a substituted or unsubstitutedalkyl group, a substituted or unsubstituted cycloalkyl group, asubstituted or unsubstituted alkenyl group, a substituted orunsubstituted alkynyl group, a substituted or unsubstituted aralkylgroup, a substituted or unsubstituted aryl group, and a substituted orunsubstituted heterocyclic group, further preferably a substituted arylgroup, or a substituted heterocyclic group, and still further preferablya substituted aryl group.

(vi) Q is preferably a hydrogen atom, a substituted or unsubstitutedalkyl group, a substituted or unsubstituted acyl group, a substituted orunsubstituted alkylsulfonyl group, or a substituted or unsubstitutedarylsulfonyl group, more preferably a hydrogen atom, a substituted orunsubstituted alkyl group, or a substituted or unsubstituted acyl group,and further preferably a hydrogen atom.

(vii) n represents an integer of 1 to 3, preferably 1 or 2, and morepreferably 2.

It is preferable that the compound represented by the formula (Y) is acompound represented by any of the following formulae (Y-1), (Y-2),(Y-3), (Y-4) and (Y-5).

In formula (Y-1), R₁, R₂, X₁, X₂, Y₁, Y₂, Z₁, and Z₂ each independentlyrepresent a monovalent group. G represents an atomic group necessary toform a 5- to 8-membered nitrogen-containing hetero ring. M represents ahydrogen atom or a cation. m₁ represents an integer of 0 to 3.

Examples of G include the same as those recited in G of theaforementioned formula (Y). Examples of the monovalent group representedby R₁, R₂, X₁, X₂, Y₁, Y₂, Z₁ and Z₂ include the same as those recitedin Q, R, X, Y and Z of the formula (Y).

In formula (Y-2), R₁, R₂, R₁₁, R₁₂, X₁, X₂, Z₁ and Z₂ each independentlyrepresent a monovalent group. L₁ represents a divalent connecting group.G₁ and G₂ each independently represent an atomic group necessary to forma 5- to 8-membered nitrogen-containing hetero ring. M represents ahydrogen atom or a cation. m₂₁ and m₂₂ each independently represent aninteger of 0 to 3.

Examples of G₁ and G₂ include the same as those recited in G of theformula (Y). Examples of the monovalent group represented by R₁, R₂,R₁₁, R₁₂, X₁, X₂, Z₁ and Z₂ include the same as those recited in Q, R,X, Y and Z of the formula (Y). Examples of the divalent grouprepresented by L₁ include the same as those recited when Q, R, X, Y andZ of the formula (Y) represent a divalent group.

In formula (Y-3), R₁, R₂, R₁₁, R₁₂, X₁, X₂, Y₁, and Y₂ eachindependently represent a monovalent group. L₂ represents a divalentconnecting group. G₁ and G₂ each independently represent an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring. Mrepresents a hydrogen atom or a cation. m₃₁ and m₃₂ each independentlyrepresent an integer of 0 to 3.

Examples of G₁ and G₂ include the same as those recited in G of theformula (Y). Examples of the monovalent group represented by R₁, R₂,R₁₁, R₁₂, X₁, X₂, Y₁, and Y₂ include the same as those recited in Q, R,X, Y and Z of the formula (Y). Examples of the divalent grouprepresented by L₂ include the same as those recited when Q, R, X, Y andZ of the formula (Y) represent a divalent group.

In formula (Y-4), R₁₁, R₁₂, X₁, X₂, Y₁, Y₂, Z₁, and Z₂ eachindependently represent a monovalent group. L₃ represents a divalentconnecting group. G₁ and G₂ each independently represent an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring. Mrepresents a hydrogen atom or a cation. m₄₁ and m₄₂ each independentlyrepresent an integer of 0 to 3.

Examples of G₁ and G₂ include the same as those recited in G of theformula (Y). Examples of the monovalent group represented by R₁₁, R₁₂,X₁, X₂, Y₁, Y₂, Z₁, and Z₂ include the same as those recited in Q, R, X,Y and Z of the formula (Y). Examples of the divalent group representedby L₃ include the same as those recited when Q, R, X, Y and Z of theformula (Y) represent a divalent group.

In formula (Y-5), R₁, R₂, R₁₁, R₁₂, Y₁, Y₂, Z₁, and Z₂ eachindependently represent a monovalent group. L₄ represents a divalentconnecting group. G₁ and G₂ each independently represent an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring. Mrepresents a hydrogen atom or a cation. m₅₁ and m₅₂ each independentlyrepresent an integer of 0 to 3.

Examples of G₁ and G₂ include the same as those recited in G of theformula (Y). Examples of the monovalent group represented by R₁, R₂,R₁₁, R₁₂, Y₁, Y₂, Z₁, and Z₂ include the same as those recited in Q, R,X, Y and Z of the formula (Y). Examples of the divalent grouprepresented by L₄ include the same as those recited when Q, R, X, Y andZ of the formula (Y) represent a divalent group.

It is preferable that the compound represented by the formula (Y) is acompound represented by any of the following formulae (Y-1), (Y-2),(Y-3), (Y-4) and (Y-5) in which the nitrogen-containing heterocyclicring formed by G, G₁ or G₂ is a S-triazine ring.

Exemplified dyes DYE-1 to DEY-26 as specific examples of the compoundrepresented by the formula (Y) are shown below. However, the dyes usedin the present invention are not limited to these compounds. Further,even though the chemical structures of the following compounds aredescribed in the form of free acids, they may be used as a salt thereof.Herein, preferable examples of the counter cation include alkali metals(for example, lithium, sodium, potassium), ammonium, and organic cations(for example, pyridinium, tetramethyl ammonium, guanidium).

The compound represented by the formula (Y) and a salt thereof may besynthesized with reference to the synthetic methods described in, forexample, JP-A Nos. 2001-279145, 2003-277661, 2003-2777662 and2004-83903.

It is preferable that the yellow ink of the invention contains thecompound represented by the formula (Y) or a salt thereof as a dye in anamount of 50% by mass to 100% by mass, based on the total dyes in theink. If the content of the compound represented by the formula (Y) or asalt thereof as a dye in the ink is within the above-described range,deterioration of the color balance owing to a drastic fading can beavoided. As a result, an image excellent in storage stability for a longtime can be obtained.

The content of the compound represented by the formula (Y) or a saltthereof in the ink is preferably from 80% by mass to 100% by mass, andmore preferably from 90% by mass to 100% by mass, based on the totaldyes in the ink.

Herein, the yellow ink of the invention may contain other yellow dyes incombination with the compound represented by the formula (Y) or a saltthereof. The other yellow dye is not particularly limited, but any knowndyes may be selectively used.

[Water-Soluble Organic Solvent]

The yellow ink contains, as a water-soluble organic solvent, at leastone glycol ether represented by formula (A) set forth below. The use ofthe glycol ether represented by the formula (A) while regulating thecontent thereof allows a stable maintenance of yellow density and yellowfading property. As a result, deterioration of the color balance owingto a fading with the lapse of time can be supressed.

Herein, the term “water-soluble” of the water-soluble organic solventmeans that the solubility in water (25° C.) is 1 g/100 g or more(hereinafter, the same definition is applied)

In formula (A), A represents an ethyleneoxy group or a propyleneoxygroup. When A represents an ethyleneoxy group, R represents a straightchain alkyl group having 1 to 4 carbon atoms. When A represents apropyleneoxy group, R represents a straight chain alkyl group having 1to 2 carbon atoms. n represents an integer of 1 or 2.

Examples of the straight chain alkyl group having 1 to 4 carbon atoms,represented by R, include a methyl group, an ethyl group, a propyl groupand a butyl group. Further, examples of the straight chain alkyl grouphaving 1 to 2 carbon atoms include a methyl group, and an ethyl group.The straight chain alkyl group may be non-substituted, or may have asubstituent.

Specific examples of the glycol ether represented by formula (A) includeethylene glycol monomethylether, ethylene glycol monoethylether,ethylene glycol monopropylether, ethylene glycol monobutylether,diethylene glycol monomethylether, diethylene glycol monoethylether,diethylene glycol monopropylether, diethylene glycol monobutylether,propylene glycol monomethylether, propylene glycol monoethylether,dipropylene glycol monomethylether, and dipropylene glycolmonoethylether.

Among these compounds, it is preferable in consideration of the effectof improving the color balance during the fading that the ethyleneglycol used in the invention has an HLB value by the Davis method of 7.0to 9.5. The term “HLB value by the Davis method” is defined by usingfundamental numbers that are determined by each individual functionalgroup (for example, a methyl group and a methylene chain are lipophilicgroups and their fundamental numbers are 0.475, whereas a hydroxyl groupis a hydrophilic group and its fundamental number is 1.9). Specifically,the HLB value is defined by the following equation:

HLB value=7+the sum of fundamental numbers of hydrophilic groups−the sumof fundamental numbers of lipophilic groups. For the same reasonsdescribed above, it is more preferable that the HLB value of the glycolether is from 8.1 to 9.1.

Among these glycol ethers, from the viewpoints that deterioration ofcolor balance of multicolor image during the fading with the lapse oftime is effectively supressed, while maintaining a satisfactory densityand hue of the yellow color, diethylene glycol monopropylether,diethylene glycol monoethylether, ethylene glycol monoethylether,diethylene glycol monomethylether, ethylene glycol monomethylether,dipropylene glycol monomethylether, or propylene glycol monomethyletheris preferable.

The yellow ink of the invention contains the glycol ether represented bythe formula (A) in an amount of 25% by mass to 100% by mass, based onthe total water-soluble organic solvent in the ink. If the content ofthe glycol ether in the invention is less than 25% by mass, thepercentage of other water-soluble organic solvent become larger, andthereby it becomes difficult to maintain a satisfactory density of theyellow color and a color balance with the lapse of time.

From the same reason as described above, the percentage of the glycolether represented by the formula (A) that occupies in the totalwater-soluble organic solvent is preferably from 30% by mass to 100% bymass, more preferably from 40% by mass to 100% by mass. The upper limitof the content of the glycol ether represented by the formula (A) ispreferably 90% by mass.

The yellow ink of the invention may contain other water-soluble organicsolvent in combination with the glycol ether represented by the formula(A) in such an amount that the effect of the invention is not lowered bythe other water-soluble organic solvent.

Examples of the other water-soluble organic solvent include alcohols(for example, methanol, ethanol, proparnol, isopropanol, butanol,isobutanol, sec-butanol, t-butanol, pentanol, hexanol, cyclohexanol,benzylalcohol), polyvalent alcohols (for example, ethylene glycol,diethylene glycol, triethylene glycol, polyethylene glycol, propyleneglycol, dipropylene glycol, polypropylene glycol, butylene glycol,hexane diol, pentane diol, glycerin, hexane triol), amines (for example,ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine,N-ethyldiethanolamine, morpholine, N-ethyl morpholine, ethylenediamine,diethylenetriamine, triethylenetetramine, polyethyleneimine,tetramethylpropylenediamine), urea, urea derivatives, and other polarsolvents (for example, formamide, N,N-dimethylformamide,N,N-dimethylacetamide, 2-pyrolidone, N-methyl-2-pyrolidone,N-vinyl-2-pyrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone,acetonitrile, acetone).

A total content of the water-soluble organic solvent in the yellow inkof the invention is preferably from 10% by mass to 80% by mass, and morepreferably from 20% by mass to 60% by mass. Herein, the water-solubleorganic solvent may be a liquid or solid compound at 25° C. Thewater-soluble organic solvent may be used in combination of two kinds ormore.

[Surfactant]

It is preferable that the inkjet recording yellow ink of the inventioncontains a surfactant in addition to the water-soluble azo dyerepresented by the formula (Y) and the glycol ether represented by theformula (A). The surfactant is contained as a surface tension adjustingagent, by which static surface tension or dynamic surface tension can beadjusted.

Examples of the surfactant include nonionic, cationic, or anionicsurfactants. In the yellow ink of the invention, it is more preferableto contain a nonionic surfactant from the viewpoints of both storagestability and ejection stability of the ink, and moreover a rapidpermeability of ink to a receiver paper.

Examples of the nonionic surfactant include polyoxyethylene alkylether,polyoxyethylene alkylarylether, polyoxyethylene fatty acid ester,sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester,polyoxyethylene alkylamine, glycerin fatty acid ester, andoxyethyleneoxypropylene blockcopolymer. Among these compounds, acetylenediol-series surfactants are preferable from the viewpoints of ejectionstability of the ink and a rapid permeability of ink to a receiverpaper. As the acetylene diol-series surfactant, acetylene glycol(preferably acetylene-series polyoxyethyleneoxide) surfactants arepreferable. Examples of the acetylene glycol surfactants includeSURFYNOLS (for example, SURFYNOL 465, manufactured by Air Product &Chemicals).

A content of the surfactant in the yellow ink is preferably from 0.001%by mass to 15% by mass, more preferably from 0.005% by mass to 10% bymass, further preferably from 0.01% by mass to 5% by mass, and stillfurther preferably from 0.1% by mass to 5% by mass, based on the totalmass of the ink.

If the content of the surfactant (especially nonionic surfactants) iswithin the above-described range, it is advantageous in that goodejection stability can be achieved.

The surface tension of the yellow ink at 25° C. is preferably from 20mN/m to 50 mN/m, and more preferably from 25 mN/m to 40 mN/m, whichvalues are common to the static surface tension and the dynamic surfacetension. If the surface tension is 50 mN/m or less, ejection stabilityis improved. Further, image quality is also improved owing to the factthat generation of bleeding, feathering and the like when multi-colorsare ejected is suppressed by the particular surface tension. Also, ifthe surface tension is 20 mN/m or more, adhesion of the ink to a surfaceof the hardware at time of ink ejection is effectively prevented by theparticular surface tension.

With respect to measurement of static surface tension, a capillary risemethod, a falling-drop method and a hanging ring method are known to beapplicable. However, a vertical plate method is adopted as the staticsurface tension measurement in the invention. The principle of thevertical plate method is explained below. When hanging a thin plate ofglass or platinum in a vertical direction so as to immerse a part of thethin plate into a liquid, the surface tension of the liquid actsdownward along the length of the contact between the liquid and the thinplate. The surface tension can be determined by balancing this downwardforce with an upward force hanging the thin plate.

With respect to measurement of dynamic surface tension, on the otherhand, a vibrating jet method, a meniscus dropping method and a maximumbubble pressure method are known to be applicable, as described in ShinJikken Kagaku Koza, vol. 18 (Kaimen to Colloid), pp. 69 90, Maruzen Co.,Ltd. (1977). In addition, the liquid membrane break method as disclosedin JP-A No. 3-2064 is also known to be applicable. However, themeasurement of dynamic surface tension in the invention is carried outusing a bubble pressure differential method. The principle of thismethod and the way to measure are explained below.

Air bubbles are generated in a surfactant-added solution renderedhomogeneous by stirring, and thereby a new air-liquid interface isformed and the surfactant molecules in the solution are gathered on thewater surface at a constant rate. When the bubble rate (the bubblegeneration rate) is made slower in making changes thereto, a greaternumber of surfactant molecules can be gathered on the bubble surface,and the maximum bubble pressure right before bubbles burst can belowered. As a result, the maximum bubble pressure (surface tension)relative to the bubble rate can be detected. For determination ofdynamic surface tension in the invention, it is possible to suitably usea method of generating air bubbles in a solution by use of two probeslarge and small, measuring a pressure difference between the two probesunder the maximum bubble pressure conditions, and therefrom calculatingthe dynamic surface tension.

If necessary, the yellow ink of the invention may properly contain, inaddition to the aforementioned components, any one or more additivessuch as a desiccation-preventing agent (wetting agent), a bleedingmodifier, an anti-bronze agent, an association promoter, a permeationpromoter, an ultraviolet absorber, an antioxidant, an antifoaming agent,a viscosity-adjusting agent, a dispersant, a dispersion stabilizer, afungicide, an anti-rusting agent, or a pH adjusting agent.

Details of these additives are described in JP-A Nos. 2007-197491 and2008-101173.

<Inkjet Recording Ink Set>

The inkjet recording ink set of the invention is composed of at least ayellow ink, a magenta ink and a cyan ink. Further, as aforementioned, atleast one of the yellow ink is at least composed of at least onewater-soluble azo dye selected from the group consisting of a compoundrepresented by the formula (Y) and a salt thereof and at least oneglycol ether represented by the formula (A), the glycol ether beingcontained in an amount of 25% by mass to 100% by mass relative to atotal amount of water-soluble organic solvent in the ink.

By using the inkjet recording ink set, it is possible to record amulti-color image (for example, a full color image). A hue of each ofthe colorants such as a pigment that are used in the inks may be changedas desired to provide a magenta tone ink, a cyan tone ink, and a yellowtone ink for recording of a full color image. Further, a black tone inkmay be used to adjust a tone. Alternatively, aside from the tones ofyellow (Y), magenta (M), and cyan (C), a red (R) tone ink, a green (G)tone ink, a blue (B) tone ink, a white (W) tone ink, or a so-calledspecific color ink in the field of graphic arts may be used.

In the inkjet recording ink set of the invention (hereinafter, sometimesreferred to as the “ink set of the invention”), a yellow ink simplycontaining a pyrazole azo-series yellow dye is not used, but rathermonoalkylene or dialkylene glycol alkylether is used as a water-solubleorganic solvent together with the pyrazole azo-series yellow dye that isused as a dye for yellow color. By the aforementioned composition thatis able to maintain both desired density and hue of yellow color eventhough a content of the yellow dye is reduced, or an amount of thewater-soluble organic solvent is increased, a color balance at the timeof fading of a multi-color image due to the lapde of time from aninitial stage after recording may be adjusted or controlled. Thereby, animage having a good color balance and excellent storage stability for along time may be obtained.

The inkjet recording ink set of the invention contains theaforementioned inkjet recording yellow ink of the invention, a magentaink containing a magenta dye, and an cyan ink containing a cyan dye. Ifnecessary, the ink set of the invention may be composed of the othercolor inks such as a black ink in addition to these inks. Details of theinkjet recording yellow ink of the invention are described above.

Each of the cyan ink, the magenta ink, and an optionally used othercolor inks such as a black ink may be composed of a dye, a water-solubleorganic solvent, a surfactant, or other additives in the same manner asthe aforementioned yellow ink. The details and preferable embodiments ofeach of the water-soluble organic solvent, the surfactant, and the otheradditives are the same as those recited in the aforementioned yellowink.

Dyes that are suitably used in the cyan ink, the magenta ink, and theblack ink are described in detail below.

[Water-Soluble Phthalocyane Dye]

Firstly, as a dye in the cyan ink, a compound represented by thefollowing formula (C-1) and a salt thereof (water-soluble phthalocyanedye) are preferable. When the water-soluble phthalocyane dye is used incombination with the compound represented by the formula (Y)(water-soluble azo yellow dye) to record an image, a color balance ofthe image can be maintained stably for a long time, and therefore such aspecific combination use of these dyes is preferable to obtain an imageexcellent in storage stability.

In formula (C-1), Q₁ to Q₄, P₁ to P₄, W₁ to W₄, and R₁ to R₄ eachindependently represent (═C(J₁)- or —N═), (═C(J₂)- or —N═), (═C(J₃)- or—N═) or (═C(J₄)- or —N═). J₁ to J₄ each independently represent ahydrogen atom or a substituent. M represents a hydrogen atom, a metalelement, a metal oxide, a metal hydroxide or a metal halide.

Four rings, namely the ring A containing “Q₁, P₁, W₁ and R₁”, the ring Bcontaining “Q₂, P₂, W₂ and R₂”, the ring C containing “Q₃, P₃, W₃ andR₃”, and the ring D containing “Q₄, P₄, W₄ and R₄” each independentlyrepresent an aromatic hydrocarbon ring or a hetero ring.

From a viewpoint of storage stability of the image, it is preferablethat at least one of the ring A to the ring D is a hetero ring. When 1or 2, or more of the ring A to the ring D are a hetero ring, anitrogen-containing hetero ring is preferable as the hetero ring. As thenitrogen-containing hetero ring, a pyridine ring, a pyrazine ring, apyrimidine or a pyridazine ring is preferable. Of these rings, apyridine ring, or a pyrazine ring is more preferable. Especially apyridine ring is preferable.

From a viewpoint of hue and color reproduction, it is preferable that atleast one of the ring A to the ring D is an aromatic hydrocarbon ring.Further, it is more preferable that at least two of the ring A to thering D is an aromatic hydrocarbon ring.

When J₁ to J₄ each independently represent a substituent, thesubstituent is preferably a electron-attractive group. Further, it ispreferable that at least one of J₁ to J₄ is a substituent having anionic hydrophilic group.

When 1 or 2, or more of the ring A to the ring D are an aromatichydrocarbon ring, they are preferably represented by the followingformula (I).

In the formula (I), “*” indicates a bond site to the phthalocyanineskeleton. G represents —SO-Z₁, —SO₂-Z₁, —SO₂NZ₂Z₃, —CONZ₂Z₃, —CO₂Z₁,—COZ₁, or a sulfo group. t represents an integer of 1 to 4.

When plural Z₁ 's are present, they may be the same or different. Z₁represents a substituted or unsubstituted alkyl group, a substituted orunsubstituted cycloalkyl group, a substituted or unsubstituted alkenylgroup, a substituted or unsubstituted alkynyl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted aryl group,or a substituted or unsubstituted heterocyclic group.

In the formula (I), Z₁ is preferably a substituted or unsubstitutedalkyl group, a substituted or unsubstituted aryl group, or a substitutedor unsubstituted heterocyclic group, and more preferably a substitutedalkyl group, or a substituted aryl group, and further preferably asubstituted alkyl group.

Z₂ and Z₃, which may be the same or different, each independentlyrepresent a hydrogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted alkenyl group, a substituted or unsubstituted alkynylgroup, a substituted or unsubstituted aralkyl group, a substituted orunsubstituted aryl group, or a substituted or unsubstituted heterocyclicgroup.

In the formula (I), Z₂ and Z₃, which may be the same or different, arepreferably a hydrogen atom, a substituted or unsubstituted alkyl group,a substituted or unsubstituted aryl group, or a substituted orunsubstituted heterocyclic group, and more preferably a hydrogen atom, asubstituted alkyl group, or a substituted aryl group, and furtherpreferably one of Z₂ and Z₃ is a hydrogen atom, and the other is asubstituted alkyl group, or a substituted aryl group.

In the formula (I), G is preferably —SO-Z₁, —SO₂-Z₁, —SO₂NZ₂Z₃,—CONZ₂Z₃, —CO₂Z₁, or —COZ₁, more preferably —SO-Z₁, —SO₂-Z₁, or—SO₂NZ₂Z₃, and further preferably —SO-Z₁.

In the formula (I), t is preferably an integer of 1 to 3, morepreferably an integer of 1 to 2, and further preferably 1.

In the water-soluble phthalocyanine dye represented by the followingformula (C-1), when 1 or 2, or more of the ring A to the ring D are anaromatic hydrocarbon ring, at least one aromatic hydrocarbon ring ispreferably represented by the following formula (II).

In the formula (II), “*” indicates a bond site to the phthalocyanineskeleton. G has the same meaning as that in the formula (I). Preferableembodiments of G are the same as those in the formula (I).

In the formula (II), t₁ represents 1 or 2. Especially, t is preferably1.

In the cyan ink used in the invention, in addition to the water-solublephthalocyanine dye represented by the formula (C-1), other cyan dye foradjusting a hue of the cyan ink may be used in such an amount that bothlight fastness and ozone resistance are not deteriorated by the othercyan dye. As the other cyan dye, for example, a dye represented by thefollowing formula (C-5), or a dye mixture thereof may be used.

M=Li and/or Na and/or K and/or NH₄

In the formula (C-5), R₁ and R₂ each independently represent a hydrogenatom or a monovalent substituent. Further, the substituent may have asubstituent. a represents an integer of 0 to 5. b represents an integerof 0 to 5. c represents an integer of 0 to 5.

Further, examples of the other cyan dye include C.I. DIRECT BLUE 1, 10,15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80, 84, 86, 87, 90, 98, 106,108, 109, 151, 156, 158, 159, 160, 168, 189, 192, 193, 194, 199, 200,201, 202, 203, 207, 211, 213, 214, 218, 225, 229, 236, 237, 244, 248,249, 251, 252, 264, 270, 280, 288, 289, 291, C. I. ACID BLUE 9, 25, 40,41, 62, 72, 76, 80, 82, 92, 106, 112, 113, 120, 127:1, 129, 138, 143,175, 181, 205, 207, 78, 220, 221, 230, 232, 247, 258, 260, 264, 271,277, 278, 279, 280, 288, 290, 326, C. I. REACTIVE BLUE 2, 3, 5, 8, 10,13, 14, 15, 17, 18, 19, 21, 25, 26, 27, 28, 29, 38, C. I. BASIC BLUE 1,3, 5, 7, 9, 22, 26, 41, 45, 46, 47, 54, 57, 60, 62, 65, 66, 69, and 71.However, the invention is not limited to these dyes.

In the cyan ink used in the invention, other dyes may be used togetherwith the compounds represented by the above-described formula (C-1) orformulae (C-1)/(C-5). The other dyes are not particularly limited, andmay be optionally selected from known dyes.

[Water-Soluble Azo Dye (Magenta Series)]

Next, as the dye in the magenta ink, a water-soluble azo dye representedby formula (M-1) set forth below is preferable. When the water-solubleazo dye is used together with the compound (yellow aqueous azo dye)represented by the above-described formula (Y) to carry out imagerecording, a color balance of the image is maintained stably for a longtime. Therefore, a combination of these dyes is preferable to obtain animage excellent in storage stability.

In the formula (M-1), A represents a residue of a 5-membered hetero ringdiazo component A-NH₂. B₁ and B₂ each independently represent —CR₁₃═ or—CR₁₄═, or alternatively one of B₁ and B₂ is a nitrogen atom, and theother is —CR₁₃═, or —CR₁₄═. R₁₁ and R₁₂ each independently represent ahydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, analkynyl group, an aralkyl group, an aryl group, a heterocyclic group, anacyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, acarbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or asulfamoyl group. Further, each of these groups may have a substituent.G, R₁₃, and R₁₄ each independently represent a hydrogen atom, a halogenatom, an alkyl group, an alkenyl group, an alkynyl group, aralkyl group,an aryl group, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, anacyl group, a hydroxyl group, an alkoxy group, an aryloxy group, asilyloxy group, an acyloxy group, a carbamoyloxy group, a heterocyclicoxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, anamino group substituted with an alkyl group, an aryl group, or aheterocyclic group, an acylamino group, a ureido group, a sulfamoylaminogroup, an alkoxycarbonylamino group, an aryloxycarbonylamino group, analkyl or arylsulfonylamino group, a nitro group, an alkyl or arylthiogroup, an alkyl or arylsulfonyl group, an alkyl or arylsulfinyl group, asulfamoyl group, a heterocyclic thio group, or an ionic hydrophilicgroup. Further, each of the above groups may have a substituent. R₁₃ andR₁₁, or R₁₁ and R₁₂ may bond with each other to form a 5- or 6-memberedring. Herein, the formula (M-1) must have at least one ionic hydrophilicgroup.

In the invention, a preferable A in the formula (M-1) is a 5-memberedhetero ring. Examples of the hetero atom include N, O, and S. The5-membered hetero ring is preferably a 5-membered nitrogen-containinghetero ring to which an aliphatic ring, an aromatic ring or other heteroring may be condensed. Preferable examples of the hetero ring includepyrazole, imidazole, triazole, thiazole, isothiazole, thiadiazole,benzothiazole, benzoxazole, and benzoisothiazole rings. Further, eachheterocyclic group may have a substituent. Among these heterocyclicgroups, those represented by the following formulae (a) to (i) arepreferable.

In the formulae (a) to (i), Rm₁ to Rm₂₀ have the same meanings as R₁₃and R₁₄ in the formula (M-1).

In the formula (M-1), B₁ and B₂ each independently represent —CR₁₃═, or—CR₁₄═, or alternatively one of B₁ and B₂ is a nitrogen atom, and theother is —CR₁₃═, or —CR₁₄═. When B₁ and B₂ represent —CR₁₃═, or —CR₁₄═,more excellent properties are obtained. From this point, theabove-described embodiment is preferable.

In the formula (M-1), it is preferable that R₁, and R₁₂ eachindependently represent a hydrogen atom, a substituted or unsubstitutedcycloalkyl group, a substituted or unsubstituted aryl group, asubstituted or unsubstituted heterocyclic group, a substituted orunsubstituted acyl group, a substituted or unsubstituted alkylsulfonylgroup, or a substituted or unsubstituted arylsulfonyl group, morepreferably a hydrogen atom, a substituted aryl group, or a substitutedheterocyclic group, and further preferably a substituted aryl group, ora substituted heterocyclic group. R₁₁ and R₁₂ is not a hydrogen atom atthe same time.

In the formula (M-1), it is preferable that G is a hydrogen atom, ahalogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaralkyl group, an aryl group, a hydroxyl group, an alkoxy group, anaryloxy group, an acyloxy group, a heterocyclic oxy group, an aminogroup substituted with an alkyl group, an aryl group, or a heterocyclicgroup, an acylamino group, an ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl orarylsulfonylamino group, an alkyl or arylthio group, a heterocyclic thiogroup, or an ionic hydrophilic group. Further, each of the above groupsmay have a substituent.

Further, it is preferable that G is a hydrogen atom, a halogen atom, analkyl group, a hydroxyl group, an alkoxy group, an aryloxy group, anacyloxy group, an amino group substituted with an alkyl group, an arylgroup, or a heterocyclic group, or an acylamino group.

Among these groups, it is more preferable that G is a hydrogen atom, anamino group substituted with an alkyl group, an aryl group, or aheterocyclic group, or an acylamino group. It is further preferable thatG is an amino group substituted with an aryl group having a substituent.

In the formula (M-1), it is preferable that R₁₃ and R₁₄ are eachindependently a hydrogen atom, an alkyl group, a cyano group, a carboxylgroup, a carbamoyl group, or an alkoxycarbonyl group. Further, each ofthe above groups may have a substituent.

In more detail, a hydrogen atom, an alkyl group, a cyano group, or acarboxyl group is more preferable. Further, it is more preferable thatR₁₃ is a hydrogen atom, and R₁₄ is an alkyl group. It is furtherpreferable that R₁₃ is a hydrogen atom, and R₁₄ is a methyl group.

As a preferable combination of A, B₁, B₂, R₁₁ to R₁₄, and G in thecompound represented by formula (M-1), compounds in which at least oneof A, B₁, B₂, R₁₁ to R₁₄, and G is an aforementioned preferable groupare preferable, and compounds in which two or more of A, B₁, B₂, R₁₁ toR₁₄, and G are each an aforementioned preferable group are morepreferable. Compounds in which all of A, B₁, B₂, R₁₁ to R₁₄, and G areaforementioned preferable groups are most preferable.

In the invention, the compound represented by the formula (M-1) ispreferably a compound represented by the formula (M-2).

In the formula (M-2), A, B₁, B₂, R₁₁ and R₁₂ each have the same meaningsas those of the formula (M-1).

a and e each independently represent an alkyl group, an alkoxy group, ahalogen atom, with the proviso that when both a and e are an alkylgroup, a total number of carbon atoms that constitute the alkyl group is3 or more. These groups may be further substituted.

b, c, and d each independently have the same meanings as R₁₃ and R₁₄ ofthe formula (M-1). a and b, or e and d may bond with each other to forma condensed ring. Herein, the formula (M-2) must have at least one ionichydrophilic group.

In the formula (M-2), A has the same meanings as A of the formula (M-1).Preferable examples of A include the same as those described above. B₁and B₂ each have the same meanings as B₁ and B₂ of the formula (M-1).Preferable examples of B₁ and B₂ include the same as those describedabove. R₁₁ and R₁₂ each have the same meanings as R₁₁ and R₁₂ of theformula (M-1). Preferable examples of R₁, and R₁₂ include the same asthose described above. a and e each independently represent an alkylgroup, an alkoxy group, a halogen atom, with the proviso that when botha and e are an alkyl group, a total number of carbon atoms thatconstitute the alkyl group is 3 or more. These groups may be furthersubstituted.

Further, it is preferable that a and e each independently represent amethyl group, an ethyl group, or an isopropyl group with an ethyl groupand an isopropyl group being more preferable. It is further preferablethat both a and e are an ethyl group or an isopropyl group. Further, b,c, and d each independently have the same meanings as R₁₃ and R₁₄ of theformula (M-1). a and b, or e and d may bond with each other to form acondensed ring. Herein, the formula (M-2) must have at least one ionichydrophilic group. Further, c is preferably a hydrogen atom, or an alkylgroup, with a hydrogen atom, or a methyl group being more preferable. band d are preferably a hydrogen atom, or an ionic hydrophilic group. Ofthese groups, a hydrogen atom, a sulfo group, or a carboxyl group ismore preferable. Especially, it is most preferable that a combination ofb and d is a hydrogen atom and a sulfo group.

As a preferable combination of A, B₁, B₂, R₁₁, R₁₂, and a to e in thecompound represented by formula (M-2), compounds in which at least oneof A, B₁, B₂, R₁₁, R₁₂, and a to e is an aforementioned preferable groupare preferable, and compounds in which two or more of A, B₁, B₂, R₁₁,R₁₂, and a to e are each an aforementioned preferable group are morepreferable. Compounds in which all of A, B₁, B₂, R₁₁, R₁₂, and a to eare aforementioned preferable groups are most preferable.

In the invention, the compound represented by the formula (M-2) ispreferably a compound represented by the formula (M-3).

In formula (M-3), Z₁₁ represents an electron withdrawing group having aHammett substituent constant σ p of 0.20 or more. Z₁₂ represents ahydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, analkynyl group, an aralkyl group, an aryl group, a heterocyclic group, oran acyl group. R₁₁, R₁₂, R₁₃, R₁₄, a, b, c, d, and e each independentlyhave the same meanings as those in the formula (M-2). Q represents ahydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaralkyl group, an aryl group, or a heterocyclic group. Further, each ofZ₁₁, Z₁₂, and Q may have a substituent. Herein, the formula (M-3) musthave at least one ionic hydrophilic group.

R₁₃ and R₁₄ in the formula (M-3) each has the same meanings as R₁₃ andR₁₄ of the formula (M-1). Preferable examples of R₁₃ and R₁₄ include thesame as those described above. R₁₁ and R₁₂ each have the same meaningsas R₁₁ and R₁₂ of the formula (M-1). Preferable examples of R₁₁ and R₁₂include the same as those described above. a, b, c, d, and e eachindependently have the same meanings as those in the formula (M-2).Preferable examples of a, b, c, d, and e include the same as thosedescribed above. The electron withdrawing group of Z₁₁ is an electronwithdrawing group having a Hammett substituent constant σ p of 0.20 ormore, and preferably 0.30 or more. The upper limit of the σ p value ispreferably 1.0.

Specific examples of the electron withdrawing group having a Hammettsubstituent constant σ p of 0.20 or more include an acyl group, anacyloxy group, a cabamoyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a cyano group, a nitro group, a dialkylphosphonogroup, diarylphosphono group, a diarylphosphinyl group, an alkylsulfinyl group, arylsulfinyl group, an alkyl sulfonyl group,arylsulfonyl group, a sulfonyloxy group, an acylthio group, a sulfamoylgroup, a thiocyanate group, a thiocarbonyl group, a halogenated alkylgroup, a halogenated alkoxy group, a halogenated aryloxy group, ahalogenated alkylamino group, a halogenated alkylthio group, aheterocyclic group, a halogen atom, an azo group, a selenocyanate group,and an aryl group substituted with other electron withdrawing grouphaving the σ p value of 0.20 or more.

Z₁₁ is preferably a cyano group, an alkyl sulfonyl group, arylsulfonylgroup, a nitro group, or a halogen atom, more preferably a cyano group,an alkyl sulfonyl group, or arylsulfonyl group, and further preferably acyano group.

Z₁₂ is preferably a hydrogen atom, an alkyl group, a cycloalkyl group,an aralkyl group, an aryl group, a heterocyclic group, or an acyl group,and more preferably an alkyl group. Each of these substituents may befurther substituted.

More specifically, the alkyl group serving as Z₁₂ encompasses an alkylgroup having a substituent and an unsubstituted alkyl group. The alkylgroup preferably has 1 to 12 carbon atoms, and more preferably 1 to 6carbon atoms, excluding any carbon atoms belonging to a substituent.

Examples of the substituent include a hydroxyl group, an alkoxy group, acyano group, a halogen atom, and an ionic hydrophilic group.

Examples of the alkyl group include a methyl group, an ethyl group, abutyl group, an isopropyl group, a t-butyl group, a hydroxyethyl group,a methoxyethyl group, a cyanoethyl group, a trifluoromethyl group, a3-sulfopropyl group, and a 4-sulfobutyl group. Among these groups, amethyl group, an ethyl group, an isopropyl group, or a t-butyl group ispreferable. Further, an isopropyl group or a t-butyl group is morepreferable. Especially, a t-butyl group is most preferable.

The cycloalkyl group serving as Z₁₂ encompasses a cycloalkyl grouphaving a substituent and an unsubstituted cycloalkyl group. Thecycloalkyl group preferably has 5 to 12 carbon atoms, excluding anycarbon atoms belonging to a substituent. Examples of the substituentinclude an ionic hydrophilic group. Examples of the cycloalkyl groupinclude a cyclohexyl group.

The aralkyl group serving as Z₁₂ encompasses an aralkyl group having asubstituent and an unsubstituted aralkyl group. The aralkyl grouppreferably has 7 to 12 carbon atoms, excluding any carbon atomsbelonging to a substituent. Examples of the substituent include an ionichydrophilic group. Examples of the aralkyl group include a benzyl group,or a 2-phenethyl group.

The aryl group serving as Z₁₂ encompasses an aryl group having asubstituent and an unsubstituted aryl group. The aryl group preferablyhas 6 to 12 carbon atoms, excluding any carbon atoms belonging to asubstituent. Examples of the substituent include an alkyl group, analkoxy group, a halogen atom, an alkylamino group, an amido group, acarbamoyl group, a sulfamoyl group, a sulfonamido group, a hydroxylgroup, an ester group and an ionic hydrophilic group. Examples of thearyl group include a phenyl group, p-tolyl group, p-methoxyphenyl group,an o-chlorophenyl group, and a m-(3-sulfopropylamino) phenyl group.

The heterocyclic group serving as Z₁₂ encompasses a heterocyclic grouphaving a substituent and an unsubstituted heterocyclic group. Theheterocyclic group preferably has a 5- or 6-membered ring. Examples ofthe substituent include an amido group, a carbamoyl group, a sulfamoylgroup, a sulfonamido group, a hydroxyl group, an ester group and anionic hydrophilic group. Examples of the heterocyclic group include a2-pyridyl group, a 2-thienyl group, a 2-thiazoly group, a2-benzothiazoly group, and a 2-furyl group.

The acyl group serving as Z₁₂ encompasses an acyl group having asubstituent and a unsubstituted acyl group. The acyl group preferablyhas 1 to 12 carbon atoms, excluding any carbon atoms belonging to asubstituent. Examples of the substituent include an ionic hydrophilicgroup. Examples of the acyl group include an acetyl group, and a benzoylgroup.

In the formula (M-3), Q represents a hydrogen atom, an alkyl group, analkenyl group, an alkynyl group, an aralkyl group, an aryl group, or aheterocyclic group. Each of these groups may be further substituted.Details of these substituents are the same as those of theabove-described R₁₃ and R₁₄.

Q is preferably an aryl group or a heterocyclic group, each of which issubstituted with an electron withdrawing group. The electron withdrawinggroup that is a substituent of Q has a Hammett substituent constant σ pof 0.20 or more, and preferably 0.30 or more. The upper limit of the σ pvalue is preferably 1.0.

Examples of the electron withdrawing group having the σ p value of 0.20or more are the same as those recited with respective to Z₁ in theformula (M-3).

More specifically, Q is preferably a heterocyclic group substituted withan electron withdrawing group. Among these heterocyclic groups,benzoxazole rings or benzothiazole rings, each of which is substitutedwith a sulfo group, a substituted or unsubstituted carbamoyl group, or asubstituted or unsubstituted sulfamoyl group, are preferable.Especially, the benzothiazole ring substituted with a sulfo group or asubstituted sulfamoyl group is more preferable.

As a preferable combination of R₁₁ to R₁₄, Z₁₁ to Z₁₂, Q, and a to e inthe compound represented by formula (M-3), compounds in which at leastone of R₁₁ to R₁₄, Z₁₁ to Z₁₂, Q, and a to e is an aforementionedpreferable group are preferable, and compounds in which two or more ofR₁₁ to R₁₄, Z₁₁ to Z₁₂, Q, and a to e are each an aforementionedpreferable group are more preferable. Compounds in which all of R₁, toR₁₄, Z₁₁ to Z₁₂, Q, and a to e are aforementioned preferable groups aremost preferable.

As an especially preferable combination of groups in the compoundrepresented by formula (M-1), combinations composed of the following (i)to (iv) are recited.

(i) Preferable examples of the hetero ring represented by A includepyrazole, imidazole, triazole, thiazole, isothiazole, thiadiazole,benzothiazole, benzoxazole, and benzoisothiazole rings. Among theserings, pyrazole, imidazole, triazole, thiazole, isothiazole, andthiadiazole rings are more preferable. Further, pyrazole, triazole,thiazole, isothiazole, and thiadiazole rings are more preferable.Especially, a pyrazole ring is most preferable.

(ii) B₁ and B₂ each independently represent —CR₁₃═ or —CR₁₄═, oralternatively one of B₁ and B₂ is a nitrogen atom, and the other is—CR₁₃═ or —CR₁₄═. It is preferable that B₁ and B₂ represent —CR₁₃═ or—CR₁₄═. Further, it is preferable that R₁₃ is a hydrogen atom (B₁ is anunsubstituted carbon), and R₁₄ is a hydrogen atom or an alkyl group (B₂is an unsubstituted carbon atom or alkyl-substituted carbon atom).Especially, it is most preferable that R₁₃ is a hydrogen atom (B₁ is anunsubstituted carbon), and R₁₄ is a methyl group (B₂ is a carbon atomsubstituted with a methyl group).

(iii) R₁₁ and R₁₂ each independently represent a hydrogen atom, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, a substituted or unsubstituted heterocyclicgroup, a substituted or unsubstituted acyl group, a substituted orunsubstituted alkylsulfonyl group, or a substituted or unsubstitutedarylsulfonyl group. Further, a hydrogen atom, a substituted aryl groupor a substituted heterocyclic group is more preferable. Furthermore, asubstituted aryl group or a substituted heterocyclic group is morepreferable. Especially, a sulfo-substituted aryl group or asulfo-substituted heterocyclic group is most preferable.

(iv) G is preferably a hydrogen atom, a halogen atom, an alkyl group, analkenyl group, an alkynyl group, an aralkyl group, an aryl group, ahydroxyl group, an alkoxy group, an aryloxy group, an acyloxy group, aheterocyclic oxy group, an amino group substituted with an alkyl group,an aryl group, or a heterocyclic group, an acylamino group, an ureidogroup, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkyl or arylsulfonylamino group, analkyl or arylthio group, a heterocyclic thio group, or an ionichydrophilic group. Further, a hydrogen atom, a halogen atom, an alkylgroup, a hydroxyl group, an alkoxy group, an aryloxy group, an acyloxygroup, an amino group substituted with an alkyl group, an aryl group, ora heterocyclic group, or an acylamino group is more preferable. Amongthese groups, a hydrogen atom, an amino group substituted with an arylor heterocyclic group, or an acylamino group is further preferable.Further, an amino group substituted with an aryl group having asubstituent is most preferable.

Of the compound represented by the formula (M-1), compounds representedby the formula (M-2) are preferable. As an especially preferablecombination of groups in the compound represented by the formula (M-2),combinations composed of the following (i) to (iv) are recited.

(i) The examples of the heterocyclic ring represented by A include thesame as A in the formula (M-1) [(i) in the formula (M-1)]. Preferableexamples are also the same as those of A in the formula (M-1).

(ii) B₁ and B₂ each have the same meanings as B₁ and B₂ in the formula(M-1) [(ii) in the formula (M-1)]. Preferable examples are also the sameas those of B₁ and B₂ in the formula (M-1).

(iii) R₁₁ and R₁₂ each have the same meanings as R₁₁ and R₁₂ in theformula (M-1) [(iii) in the formula (M-1)]. Preferable examples alsoinclude the same as those of R₁, and R₁₂ in the formula (M-1).

(iv) a and e are preferably an alkyl group or a halogen atom. When botha and e are an alkyl group, they are an unsubstituted alkyl group, and atotal number of carbon atoms of a and e is 3 or more (preferably 5 orless). It is preferable that a, b, c, and d each represent a hydrogenatom, a halogen atom, an alkyl group or an ionic hydrophilic group (itis more preferable that they are independently a hydrogen atom, an alkylgroup having 1 to 4 carbon atoms, or an ionic hydrophilic group). It isfurthermore preferable that a and e each independently represent amethyl group, an ethyl group, or an isopropyl group. Especially, it ismost preferable that both a and e are equally an ethyl group or anisopropyl group. Further, c is preferably a hydrogen atom, or an alkylgroup, and especially preferably a hydrogen atom or a methyl group.Further, it is preferable that b and d each independently represent ahydrogen atom or an ionic hydrophilic group. It is more preferable thatb and d each independently represent a hydrogen atom, a sulfo group or acarboxyl group. Especially, it is most preferable that a combination ofb and d is a hydrogen atom and a sulfo group.

Of the compound represented by the formula (M-2), compounds representedby the formula (M-3) are especially preferable. As an especiallypreferable combination of groups in the compound represented by theformula (M-3), combinations composed of the following (i) to (vi) arerecited (combination embodiment M).

(i) Z₁₁ is an electron withdrawing group having a Hammett substituentconstant σ p of 0.20 or more, and preferably 0.3 or more. The upperlimit of the σ p value is preferably 1.0. Z₁₁ is more preferably a cyanogroup, an alkyl sulfonyl group, arylsulfonyl group, a nitro group or ahalogen atom, more preferably a cyano group, an alkyl sulfonyl group oran arylsulfonyl group, and further preferably a cyano group, an alkylsulfonyl group or an arylsulfonyl group. Especially, a cyano group ismost preferable.

(ii) Z₁₂ is preferably a hydrogen atom, an alkyl group, a cycloalkylgroup, an aralkyl group, an aryl group, a heterocyclic group or an acylgroup, and more preferably an alkyl group. Each of these substituentsmay be further substituted. More specifically, the alkyl group servingas Z₁₂ encompasses an alkyl group having a substituent and anunsubstituted alkyl group. The alkyl group preferably has 1 to 12 carbonatoms, and more preferably 1 to 6 carbon atoms, excluding any carbonatoms belonging to a substituent. Examples of the substituent include ahydroxyl group, an alkoxy group, a cyano group, a halogen atom, and anionic hydrophilic group. Among these groups, a methyl group, an ethylgroup, a butyl group, an isopropyl group, a t-butyl group, ahydroxyethyl group, a methoxyethyl group, a cyanoethyl group, atrifluoromethyl group, a 3-sulfopropyl group or a 4-sulfobutyl group ispreferable. Further, an isopropyl group or a t-butyl group is morepreferable. Especially, a t-butyl group is most preferable.

(iii) Q represents a hydrogen atom, an alkyl group, an alkenyl group, analkynyl group, an aralkyl group, an aryl group or a heterocyclic group.Each of these groups may be further substituted. Q is preferably an arylgroup or a heterocyclic group, each of which is substituted with anelectron withdrawing group. The electron withdrawing group that is asubstituent of Q has a Hammett substituent constant σ p of 0.20 or more,and preferably 0.30 or more. The upper limit of the σ p value ispreferably 1.0. More specifically, Q is preferably a heterocyclic groupsubstituted with an electron withdrawing group. Among these heterocyclicgroups, benzoxazole rings or benzothiazole rings, each of which issubstituted with a sulfo group, a substituted or unsubstituted carbamoylgroup, or a substituted or unsubstituted sulfamoyl group, arepreferable. Especially, the benzothiazole ring substituted with a sulfogroup or a substituted sulfamoyl group is more preferable.

(iv) a, b, c, d, and e each independently have the same meanings asthose in the formula (M-2)[(iv) in the formula (M-2)]. Preferableexamples of a, b, c, d, and e are also the same as those in the formula(M-1).

(v) R₁₃ and R₁₄ each independently have the same meanings as R₁₃ and R₁₄in the formula (M-1). Preferable examples of R₁₃ and R₁₄ also includethe same as those in the formula (M-1).

(vi) R₁₁ and R₁₂ each independently have the same meanings as R₁₁ andR₁₂ in the formula (M-2) [(iii) in the formula (M-2)]. Preferableexamples of R₁₁ and R₁₂ also include the same as those in the formula(M-2).

The compound (azo dye) represented by the formula (M-1), (M-2), or (M-3)has at least one (preferably from 3 to 6) ionic hydrophilic group in itsmolecule. Examples of the ionic hydrophilic group include a sulfo group,a carboxyl group, a phosphono group, and a quaternary ammonium group. Asthe ionic hydrophilic group, a carboxyl group, a phosphono group or asulfo group are preferable, and a carboxyl group or a sulfo group aremore preferable. Especially, it is most preferable that at least one ofthe ionic hydrophilic groups is a sulfo group. Each of the carboxylgroup, the phosphono group, and the sulfo group may be a salt thereof.Examples of the counter ion for forming a salt include ammonium ion,alkali metal ions (for example, lithium, sodium, potassium), and organiccations (for example, tetramethylammonium ion, tetramethylguanidium ion,tetramethylphosphonium ion). Among these counter ions, alkali metal ionsare preferable. Among these alkali metal ions, potassium ion, sodium ionor lithium ion is preferable. Especially, lithium ion is mostpreferable. In consideration of both enhancement of solubility andsuppression of bronze in the ink jet printing, the combination composedof a sulfo group as the ionic hydrophilic group and a lithium ion as acounter ion is most preferable.

The azo dye has, in its molecule, preferably from 3 to 6 ionichydrophilic groups, more preferably from 3 to 6 sulfo groups, andfurther preferably from 3 to 5 sulfo groups.

Herein, the magenta ink of the invention may contain other magenta dyesin combination with the compound represented by the above-describedformula. The other magenta dye is not particularly limited, but anyknown dyes may be selectively used.

As described above, a preferable embodiment of the inkjet recording inkset of the invention is a form including a yellow ink containing anaqueous yellow dye represented by the formula (Y) in which G is aS-triazine ring, R is a secondary or tertiary alkyl group, X is a cyanogroup, Y is a hydrogen atom, Z is a substituted aryl group, Q is ahydrogen atom, n is 1 or 2; and a cyan ink containing a water-solublephthalocyanine dye represented by the formula (C-1) in which all of thering A, the ring B, the ring C, and the ring D is represented by theformula (I), or (II), G is —SO₂-Z₁ wherein Z, is a substituted alkylgroup, and t is 1 or 2; and a magenta ink containing an aqueous azo dyerepresented by the formula (M-3) which has the above-describedcombination embodiment M.

[Water-Soluble Azo Dye (Black-Series)]

Next, as a dye in the black ink, a water-soluble azo dye represented bythe following formula (B-1) is preferable. When the water-soluble azodye is used to record an image together with the compound (yellowaqueous azo dye) represented by the above-described formula (Y), a colorbalance of the image is maintained stably for a long time. Therefore, acombination of these dyes is preferable to obtain an image excellent instorage stability.

In the formula (B-1), A represents a monovalent aromatic group orheterocyclic group, which may be substituted. B represents a divalentaromatic group or heterocyclic group, which may be substituted. T₁ andT₂ each independently represent ═CR₄₃— or —CR₄₄═. Alternatively, one ofT₁ and T₂ is a nitrogen atom, and the other is ═CR₄₃— or —CR₄₄═. V₁, R₄₃and R₄₄ each independently represent a hydrogen atom, a halogen atom, analkyl group, an alkenyl group, an alkynyl group, an aralkyl group, anaryl group, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxyl group, analkoxy group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group which may include analkylamino group, an arylamino group, and a heterocyclic amino group, anacylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl orarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkyl or arylthio group, a heterocyclic thio group, an alkylor arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl orarylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group, ora sulfo group. Further, each of the above groups may have a substituent.R₄₁ and R₄₂ each independently represent a hydrogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkyl or arylsulfonylgroup, or a sulfamoyl group, with the proviso that both R₄₁ and R₄₂ arenot a hydrogen atom at the same time. Further, each of the above groupsmay have a substituent. R₄₃ and R₄₁, or R₄₁ and R₄₂ may bond with eachother to form a 5- or 6-membered ring.

The formula (B-1) is explained in detail.

In the formula (B-1), A preferably represents a monovalent aromatic orheterocyclic group, which may be substituted. More specifically, A ispreferably a substituted phenyl group, a substituted naphthyl group, ora substituted or unsubstituted heterocyclic group. Among these groups, aphenyl or naphthyl group substituted with an ionic hydrophilic group,and a substituted 5- or 6-membered nitrogen-containing heterocyclic ringare preferable. Especially, a phenyl or naphthyl group each substitutedwith a sulfo group which may be a salt thereof, or a carboxyl groupwhich may be a salt thereof is preferable. Further, a phenyl or naphthylgroup each substituted with two or more sulfo groups or carboxyl groups,each of which may be a salt thereof is preferable. Further, a naphthylgroup substituted with two or three sulfo groups which may be a saltthereof is most preferable.

In the formula (B-1), B represents a divalent aromatic or heterocyclicgroup, which may be substituted. More specifically, B is preferably asubstituted 5- or 6-membered heterocyclic group, and more preferably asubstituted 5-membered heterocyclic group. The 5- or 6-membered heteroring means a 5- or 6-membered ring containing a hetero atom. Examples ofthe hetero atom include N, S, and O.

In the hetero ring represented by B, an alicyclic ring, an aromaticring, or another hetero ring may be condensed. Further, the condensedring may have a substituent. The hetero ring represented by B may be asaturated or unsaturated hetero ring, but is preferably an unsaturatedhetero ring. When the hetero ring is a nitrogen-containing hetero ring,the nitrogen may be quaternized. Further, with respect to a hetero ringcapable of forming a tautomer, even where only one form of the tautomeris described, the hetero ring may also include other forms of thetautomer.

Of the hetero ring represented by B, especially preferable hetero ringsare pyridine, pyrazine, pyrimidine, pyridazine, thiophene, thiazole,imidazole, benzothiazole, and thienothiazole rings.

In the formula (B-1), T₁ and T₂ each independently represent ═CR₄₃— or—CR₄₄═. Alternatively, one of T₁ and T₂ is a nitrogen atom, and theother is ═CR₄₃— or —CR₄₄═-However, when T₁ and T₂ each independentlyrepresent ═CR₄₃— or —CR₄₄═, it is advantageous in that more excellentproperties are obtained.

In the formula (B-1), R₄₁ and R₄₂ each independently represent ahydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaralkyl group, an aryl group, a heterocyclic group, an acyl group, analkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, analkyl or arylsulfonyl group, or a sulfamoyl group. Further, each of theabove groups may have a substituent. Among these groups, a hydrogenatom, an alkyl group, an aryl group, a heterocyclic group, an acylgroup, or an alkyl or arylsulfonyl group is preferable, and a hydrogenatom, an alkyl group, an aryl group, or a heterocyclic group is morepreferable. Further, a hydrogen atom, a substituted aryl group, or asubstituted heterocyclic group is more preferable. Still further, ahydrogen atom, or a substituted aryl group is most preferable. However,both R₄₁, and R₄₂ are not a hydrogen atom at the same time. R₄₃ and R₄₁,or R₄₁ and R₄₂ may bond with each other to form a 5- or 6-membered ring.

In the formula (B-1), V₁ is preferably a hydrogen atom, a halogen atom,an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, anaryl group, a heterocyclic group, a hydroxyl group, an alkoxy group, anaryloxy group, a heterocyclic oxy group, a silyloxy group, an acyloxygroup, an amino group which may include an alkylamino group, anarylamino group, and a heterocyclic amino group, an acylamino group, aureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkyl or arylthio group, or aheterocyclic thio group. Further, each of the above groups may have asubstituent.

Further, V₁ is more preferably a hydrogen atom, a halogen atom, an alkylgroup, a hydroxyl group, an alkoxy group, an aryloxy group, aheterocyclic oxy group, a silyloxy group, an acyloxy group, an aminogroup which may include an alkylamino group, an arylamino group, and aheterocyclic amino group, or an acylamino group, more preferably ahydrogen atom, an amino group which may include an alkylamino group, anarylamino group, and a heterocyclic amino group, or an acylamino group,further preferably an amino group having a substituent, and stillfurther preferably an amino group substituted with an aryl group havingan ionic hydrophilic group as the substituent. Namely, such thesubstituted anilino group is most preferable.

As an especially preferable combination of groups in the compoundrepresented by the formula (B-1), combinations composed of the following(i) to (v) are recited.

(i) A is preferably a substituted phenyl or a substituted naphthylgroup, or a substituted or unsubstituted heterocyclic group, and morepreferably a phenyl or naphthyl group, each of which is substituted withan ionic hydrophilic group, or a 5- or 6-membered heterocyclic grouphaving a substituent, and more preferably a phenyl or naphthyl groupsubstituted with a sulfo group which may be a salt thereof, or acarboxyl group which may be a salt thereof, and further preferably aphenyl or naphthyl group substituted with two or more sulfo groups orcarboxyl groups, each of which may be a salt thereof, and still furtherpreferably a naphthyl group substituted with two or three sulfo groupswhich may be a salt thereof.

(ii) B is preferably a substituted 5- or 6-membered heterocyclic group,and more preferably a substituted 5-membered heterocyclic group. Of thehetero ring represented by B, especially preferable rings are pyridine,pyrazine, pyrimidine, pyridazine, thiophene, thiazole, imidazole,benzothiazole, and thienothiazole rings.

(iii) T₁ and T₂ each independently represent ═CR₄₃— or —CR₄₄═.Alternatively, one of T₁ and T₂ is a nitrogen atom, and the other is═CR₄₃— or —CR₄₄═. When T₁ and T₂ each independently represents ═CR₄₃— or—CR₄₄═, it is advantageous in that more excellent properties areobtained.

(iv) R₄₁ and R₄₂ are preferably a hydrogen atom, an alkyl group, an arylgroup, a heterocyclic group, an acyl group, or an alkyl or arylsulfonylgroup, more preferably a hydrogen atom, an alkyl group, an aryl group,or a heterocyclic group, further preferably a hydrogen atom, asubstituted aryl group, or a substituted heterocyclic group, and stillfurther preferably a hydrogen atom, or a substituted aryl group.However, both R₄₁ and R₄₂ are not a hydrogen atom at the same time. R₄₃and R₄₁, or R₄₁ and R₄₂ may bond with each other to form a 5- or6-membered ring.

(v) V₁ is preferably a hydrogen atom, a halogen atom, an alkyl group, ahydroxyl group, an alkoxy group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, an amino group which mayinclude an alkylamino group, an arylamino group, and a heterocyclicamino group, or an acylamino group, more preferably a hydrogen atom, anamino group which may include an alkylamino group, an arylamino group,and a heterocyclic amino group, or an acylamino group, furtherpreferably an amino group having a substituent, and still furtherpreferably an amino group substituted with an aryl group having an ionichydrophilic group as the substituent. Namely, such the substitutedanilino group is most preferable.

As a preferable combination of A, B, T₁, T₂, R₄₁, R₄₂, and V₁ in the dyerepresented by formula (B-1), compounds in which at least one of A, B,T₁, T₂, R₄₁, R₄₂, and V₁ is an aforementioned preferable group arepreferable, and compounds in which two or more of A, B, T₁, T₂, R₄₁,R₄₂, and V₁ are each an aforementioned preferable group are morepreferable. Compounds in which all of A, B, T₁, T₂, R₄₁, R₄₂, and V₁ areaforementioned preferable groups are most preferable.

Of the compound represented by the formula (B-1), compounds representedby the following formula (B-2) are preferable.

In the formula (B-2), X represents a nitrogen atom or ═CW₁—, wherein W₁represents an electron withdrawing group having a Hammett substituentconstant σ p of 0.20 or more. A, V₁, T₁, T₂, R₄₁ and R₄₂ each has thesame meanings as A, V₁, T₁, T₂, R₄₁, and R₄₂ of the formula (B-1). W hasthe same meaning as V₁ of the formula (B-1).

The formula (B-2) is explained in detail below.

In the formula (B-2), W is preferably a substituted phenyl group, asubstituted or unsubstituted naphthyl group, or a substituted orunsubstituted heterocyclic group. As the hetero ring serving as theheterocyclic group, pyrrole, thiophene, imidazole, thiazole,benzothiazole, pyridine, and pyridazine rings are exemplified. Asubstituted phenyl group (especially p-substituted phenyl group), asubstituted or unsubstituted β-naphthyl group, or a group derived from apyridine ring or a thiazole ring is especially preferable.

In the formula (B-2), X represents a nitrogen atom or ═CW₁—, wherein W₁represents an electron withdrawing group having a Hammett substituentconstant σ p of 0.20 or more, preferably 0.30 or more, and morepreferably 0.45 or more, and further preferably 0.60 or more. The upperlimit of the σ p value is preferably 1.0. In more detail, W₁ ispreferably an acyl group having 2 to 20 carbon atoms, an alkoxycarbonylgroup having 2 to 20 carbon atoms, a nitro group, a cyano group, analkylsulfonyl group having 2 to 20 carbon atoms, an arylsulfonyl grouphaving 6 to 20 carbon atoms, a carbamoyl group having 1 to 20 carbonatoms, or a halogenated alkyl group having 1 to 20 carbon atoms. Amongthese groups, a cyano group, an alkylsulfonyl group having 1 to 20carbon atoms, or an arylsulfonyl group having 6 to 20 carbon atoms ismore preferable. Especially, a cyano group is most preferable.

In the formula (B-2), A has the same meaning as A in the formula (B-1).Preferable examples of A are also the same as those of A. T₁ and T₂ eachhave the same meanings as those in the formula (B-1). Preferableexamples of T₁ and T₂ are also the same as those of T and T₂. R₄₁ andR₄₂ each have the same meanings as those of the formula (B-1).Preferable examples of R₄₁ and R₄₂ are also the same as those of R₄₁ andR₄₂. V₁ has the same meaning as V₁ in the formula (B-1). Preferableexamples of V₁ are also the same as those of V₁.

As an especially preferable combination of groups in the compoundrepresented by the formula (B-2), combinations composed of the following(i) to (vi) are recited.

(i) W is preferably a substituted phenyl group, a substituted orunsubstituted naphthyl group, or a substituted or unsubstitutedheterocyclic group. As the hetero ring serving as the heterocyclicgroup, pyrrole, thiophene, imidazole, thiazole, benzothiazole, pyridine,and pyridazine rings are exemplified. A substituted phenyl group(especially p-substituted phenyl group), a substituted or unsubstitutedβ-naphthyl group, or a group derived from a pyridine ring or a thiazolering is especially preferable.

(ii) X represents a nitrogen atom or ═CW₁—, wherein W₁ represents anelectron withdrawing group having a Hammett substituent constant σ p of0.20 or more. In more detail, W₁ is preferably an acyl group having 2 to20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, anitro group, a cyano group, an alkylsulfonyl group having 1 to 20 carbonatoms, an arylsulfonyl group having 6 to 20 carbon atoms, a carbamoylgroup having 1 to 20 carbon atoms, or a halogenated alkyl group having 1to 20 carbon atoms. Among these groups, a cyano group, an alkylsulfonylgroup having 1 to 20 carbon atoms, or an arylsulfonyl group having 6 to20 carbon atoms is more preferable. Especially, a cyano group is mostpreferable.

(iii) A is preferably a substituted phenyl group, a substituted naphthylgroup, or a substituted or unsubstituted heterocyclic group. Among thesegroups, a phenyl or naphthyl group substituted with an ionic hydrophilicgroup, and a substituted 5- or 6-membered nitrogen-containingheterocyclic ring are preferable. Especially, a phenyl or naphthyl groupeach substituted with a sulfo group which may be a salt thereof, or acarboxyl group which may be a salt thereof is preferable. Further, anaphthyl group substituted with two or three sulfo groups which may be asalt thereof is most preferable.

(iv) T₁ and T₂ each independently represents ═CR₄₃— or —CR₄₄═.Alternatively, one of T₁ and T₂ is a nitrogen atom, and the other is═CR₄₃— or —CR₄₄═. When T₁ and T₂ each independently represent ═CR₄₃— or—CR₄₄═, it is advantageous in that more excellent properties areobtained.

(v) R₄₁ and R₄₂ are preferably a hydrogen atom, an alkyl group, an arylgroup, a heterocyclic group, an acyl group, or an alkyl or arylsulfonylgroup, more preferably a hydrogen atom, an alkyl group, an aryl group,or a heterocyclic group, further preferably a hydrogen atom, asubstituted aryl group, or a substituted heterocyclic group, and stillfurther preferably a hydrogen atom or a substituted aryl group. However,both R₄₁ and R₄₂ is not a hydrogen atom at the same time. R₄₃ and R₄₁,or R₄₁ and R₄₂ may bond with each other to form a 5- or 6-membered ring.

(vi) V₁ is preferably a hydrogen atom, a halogen atom, an alkyl group, ahydroxyl group, an alkoxy group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, an amino group which mayinclude an alkylamino group, an arylamino group, and a heterocyclicamino group, or an acylamino group, more preferably a hydrogen atom, anamino group which may include an alkylamino group, an arylamino group,and a heterocyclic amino group, or an acylamino group, furtherpreferably an amino group having a substituent, and still furtherpreferably an amino group substituted with an aryl group having an ionichydrophilic group as the substituent. Namely, such the substitutedanilino group is most preferable.

As a preferable combination of W, X, A, T₁, T₂, R₄₁, R₄₂, and V₁ in thedye represented by formula (B-2), compounds in which at least one of W,X, A, T₁, T₂, R₄, R₄₂, and V₁ is an aforementioned preferable group arepreferable, and compounds in which two or more of W, X, A, T₁, T₂, R₄₁,R₄₂, and V₁ are each an aforementioned preferable group are morepreferable. Compounds in which all of W, X, A, T₁, T₂, R₄₁, R₄₂, and V₁are aforementioned preferable groups are most preferable.

Of the compound represented by the formula (B-2), compounds representedby the following formula (B-3) are preferable.

In the formula (B-3), V₁, W, X, A, T₁, T₂, R₄₁, and R₄₂ each have thesame meanings as V₁, W, X, A, T₁, T₂, R₄₁, and R₄₂ of the formula (B-2),and X₁, X₂, X₃, X₄, X₅, X₆, and X₇ each have the same meanings as V₁ ofthe formula (B-1).

The formula (B-3) is explained in detail below.

In the formula (B-3), a monovalent group represented by each of X₁, X₂,X₃, X₄, X₅, X₆, and X₇ is a hydrogen atom, or a monovalent substituent.The monovalent substituent is explained in detail below. Examples of themonovalent substituent include a halogen atom, an alkyl group, acycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group,an aryl group, a heterocyclic group, a cyano group, a hydroxyl group, anitro group, an alkoxy group, an aryloxy group, a silyloxy group, aheterocyclic oxy group, an acyloxy group, a carbamoyloxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino groupwhich may be an alkylamino group or an arylamino group, an acylaminogroup (amido group), an aminocarbonylamino group (ureido group), analkoxycarbonylamino group, an aryloxycarbonylamino group, asulfamoylamino group, an alkyksulfonylamino group, an arylsulfonylaminogroup, an alkylthio group, arylthio group, a heterocyclic thio group, asulfamoyl group, an alkylsulfinyl group, an arylsulfinyl group, analkylsulfonyl group, an arylsulfonyl group, an acyl group, anaryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, asulfo group which may be a salt thereof, a carboxyl group which may be asalt thereof, a phosphono group which may be a salt thereof, aquaternary ammonium group, a phosphino group, a phosphinyl group, aphosphinyloxy group, a phosphinylamino group, a silyl group, an azogroup, or an imido group. Further, each of the above groups may have asubstituent.

X₁, X₂, X₃, X₄, X₅, X₆, and X₇ is preferably a hydrogen atom, a halogenatom, an alkyl group, an aryl group, a heterocyclic group, a cyanogroup, an alkoxy group, an amido group, an ureido group, analkylsulfonylamino group, an arylsulfonylamino group, a sulfamoyl group,an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, analkoxycarbonyl group, a sulfo group which may be a salt thereof, acarboxyl group which may be a salt thereof, a hydroxyl group which maybe a salt thereof, a phosphono group which may be a salt thereof, or aquaternary ammonium group. Further, a hydrogen atom, a halogen atom, analkyl group, a sulfo group including a salt thereof, a carboxyl groupwhich may be a salt thereof, or a hydroxyl group which may be a saltthereof is more preferable. Among these groups, a hydrogen atom, a sulfogroup which may be a salt thereof, or a carboxyl group which may be asalt thereof is further preferable. It is especially preferable that atleast one of X₁, X₂, X₃, X₄, X₅, X₆, and X₇ is a sulfo group which maybe a salt thereof, or a carboxyl group which may be a salt thereof.

In the formula (B-3), W has the same meaning as W of the formula (B-2).Preferable examples of W are also the same as those of W. X has the samemeaning as X of the formula (B-2). Preferable examples of X are also thesame as those of X. T₁ and T₂ each have the same meanings as T₁ and T₂of the formula (B-2). Preferable examples of T₁ and T₂ are also the sameas those of T₁ and T₂. R₄₁ and R₄₂ each have the same meanings as R₄₁and R₄₂ of the formula (B-2). Preferable examples of R₄₁ and R₄₂ arealso the same as those of R₄₁ and R₄₂. V₁ has the same meaning as V₁ ofthe formula (B-2). Preferable examples of V₁ are also the same as thoseof V₁.

As an especially preferable combination of groups in the compoundrepresented by the formula (B-3), combinations composed of the following(i) to (vi) are recited.

(i) X₁, X₂, X₃, X₄, X₅, X₆, and X₇ is preferably a hydrogen atom, ahalogen atom, an alkyl group, an aryl group, a heterocyclic group, acyano group, an alkoxy group, an amido group, an ureido group, analkylsulfonylamino group, an arylsulfonylamino group, a sulfamoyl group,an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, or analkoxycarbonyl group, a sulfo group which may be a salt thereof, acarboxyl group which may be a salt thereof, a hydroxyl group which maybe a salt thereof, a phosphono group which may be a salt thereof, or aquaternary ammonium group. Further, a hydrogen atom, a halogen atom, analkyl group, a sulfo group which may be a salt thereof, a carboxyl groupwhich may be a salt thereof, or a hydroxyl group which may be a saltthereof is more preferable. Among these groups, a hydrogen atom, a sulfogroup which may be a salt thereof, or a carboxyl group which may be asalt thereof is further preferable. It is especially preferable that atleast one of X₁, X₂, X₃, X₄, X₅, X₆, and X₇ is a sulfo group which maybe a salt thereof, or a carboxyl group which may be a salt thereof.

(ii) W is preferably a substituted phenyl group, a substituted orunsubstituted naphthyl group, or a substituted or unsubstitutedheterocyclic group. As the hetero ring serving as the heterocyclicgroup, pyrrole, thiophene, imidazole, thiazole, benzothiazole, pyridine,and pyridazine rings are exemplified. A substituted phenyl group(especially p-substituted phenyl group), a substituted or unsubstitutedβ-naphthyl group, or a group derived from a pyridine ring or a thiazolering is especially preferable.

(iii) X represents a nitrogen atom or ═CW₁—, wherein W₁ represents anelectron withdrawing group having a Hammett substituent constant σ p of0.20 or more. In more detail, W₁ is preferably an acyl group having 2 to20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, anitro group, a cyano group, an alkylsulfonyl group having 1 to 20 carbonatoms, an arylsulfonyl group having 6 to 20 carbon atoms, a carbamoylgroup having 1 to 20 carbon atoms, or a halogenated alkyl group having 1to 20 carbon atoms. Among these groups, a cyano group, an alkylsulfonylgroup having 1 to 20 carbon atoms, or an arylsulfonyl group having 6 to20 carbon atoms is more preferable. Especially, a cyano group is mostpreferable.

(iv) T₁ and T₂ each independently represents ═CR₄₃— or —CR₄₄═.Alternatively, one of T₁ and T₂ is a nitrogen atom, and the other is═CR₄₃— or —CR₄₄═. When T₁ and T₂ each independently represent ═CR₄₃— or—CR₄₄═, it is advantageous in that more excellent properties areobtained.

(v) R₄₁ and R₄₂ are preferably a hydrogen atom, an alkyl group, an arylgroup, a heterocyclic group, an acyl group, or an alkyl or arylsulfonylgroup, more preferably a hydrogen atom, an alkyl group, an aryl group,or a heterocyclic group, further preferably a hydrogen atom, asubstituted aryl group, or a substituted heterocyclic group, and stillfurther preferably a hydrogen atom, or a substituted aryl group.However, both R₄₁ and R₄₂ is not a hydrogen atom at the same time. R₄₃and R₄₁, or R₄₁ and R₄₂ may bond with each other to form a 5- or6-membered ring.

(vi) V₁ is preferably a hydrogen atom, a halogen atom, an alkyl group, ahydroxyl group, an alkoxy group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, an amino group which may bean alkylamino group, an arylamino group, or a heterocyclic amino group,or an acylamino group, more preferably a hydrogen atom, an amino groupwhich may be an alkylamino group, an arylamino group, or a heterocyclicamino group; or an acylamino group, further preferably an amino grouphaving a substituent, and still further preferably an amino groupsubstituted with an aryl group having an ionic hydrophilic group as thesubstituent. Namely, such the substituted anilino group is mostpreferable.

As a preferable combination of X₁-X₇, W, X, T₁, T₂, V₁, R₄₁, and R₄₂ inthe dye represented by formula (B-3), compounds in which at least one ofX₁-X₇, W, X, T₁, T₂, V₁, R₄₁, and R₄₂ is an aforementioned preferablegroup are preferable, and compounds in which two or more of X₁-X₇, W, X,T₁, T₂, V₁, R₄₁, and R₄₂ are each an aforementioned preferable group aremore preferable. Compounds in which all of X₁-X₇, W, X, T₁, T₂, V₁ R₄₁,and R₄₂ are aforementioned preferable groups are most preferable.

Of the compound represented by the formula (B-3), compounds representedby the following formula (B-4), or formula (B-5) are preferable.

In the formula (B-4), R₄₁, R₄₂ and R₄₃ each have the same meanings asR₄₁, R₄₂ and R₄₃ of the formula (B-1). R₄₄ has the same meaning as R₄₄of the formula (B-1) R₄₅ and R₄₆ each have the same meanings as R₄₁ andR₄₂ of the formula (B-3). W has the same meaning as W of the formula(B-3). X₁, X₂, X₃, X₄, X₅, X₆, and X₇ each have the same meanings as X₁,X₂, X₃, X₄, X₅, X₆, and X₇ of the formula (B-3).

In the formula (B-5), R₄₁, R₄₂, and R₄₃ each have the same meanings asR₄₁, R₄₂, and R₄₃ of the formula (B-1). R₄₄ has the same meaning as R₄₄of the formula (B-1). R₄₅ and R₄₆ each have the same meanings as R₄₁ andR₄₂ of the formula (B-3). W has the same meaning as W of the formula(B-3). W₁₁ has the same meaning as W₁ of the formula (B-2). X₁, X₂, X₃,X₄, X₅, X₆, and X₇ each have the same meanings as X₁, X₂, X₃, X₄, X₅,X₆, and X₇ of the formula (B-3).

The formula (B-4) is explained in detail below.

In the formula (B-4), X₁, X₂, X₃, X₄, X₅, X₆, and X₇ each have the samemeanings as X₁, X₂, X₃, X₄, X₅, X₆, and X₇ of the formula (B-3).Preferable examples of X₁, X₂, X₃, X₄, X₅, X₆, and X₇ are also the sameas those of X₁, X₂, X₃, X₄, X₅, X₆, and X₇ of the formula (B-3). W hasthe same meaning as W of the formula (B-3). Preferable examples of W arealso the same as those of W of the formula (B-3). R₄₁ and R₄₂ each havethe same meanings as R₄₁ and R₄₂ of the formula (B-1). Preferableexamples of R₄₁ and R₄₂ are also the same as those of P₄₁ and R₄₂ of theformula (B-1). R₄₃ and 44 each have the same meanings as those of theformula (B-1). Preferable examples of R₄₃ and R₄₄ are also the same asthose of R₄₃ and R₄₄ of the formula (B-1). R₄₅ and R₄₆ each have thesame meanings as R₄₁ and R₄₂ of the formula (B-3). Preferable examplesof R₄₅ and R₄₆ are also the same as those of R₄₁ and R₄₂ of the formula(B-3).

As an especially preferable combination of groups in the compoundrepresented by the formula (B-4), combinations composed of the following(i) to (v) are recited.

(i) X₁, X₂, X₃, X₄, X₅, X₆, and X₇ is a hydrogen atom, a halogen atom,an alkyl group, an aryl group, a heterocyclic group, a cyano group, analkoxy group, an amido group, an ureido group, an alkylsulfonylaminogroup, an arylsulfonylamino group, a sulfamoyl group, an alkylsulfonylgroup, an arylsulfonyl group, a carbamoyl group, an alkoxycarbonylgroup, a sulfo group which may be a salt thereof, a carboxyl group whichmay be a salt thereof, a hydroxyl group which may be a salt thereof, aphosphono group which may be a salt thereof, or a quaternary ammoniumgroup. Further, a hydrogen atom, a halogen atom, an alkyl group, a sulfogroup which may be a salt thereof, a carboxyl group which may be a saltthereof, or a hydroxyl group which may be a salt thereof is morepreferable. Among these groups, a hydrogen atom, a sulfo group which maybe a salt thereof, or a carboxyl group which may be a salt thereof isfurther preferable. It is especially preferable that at least one of X₁,X₂, X₃, X₄, X₅, X₆, and X₇ is a sulfo group which may be a salt thereof,or a carboxyl group which may be a salt thereof.

(ii) W is preferably a substituted phenyl group, a substituted orunsubstituted naphthyl group, or a substituted or unsubstitutedheterocyclic group. As the hetero ring serving as the heterocyclicgroup, pyrrole, thiophene, imidazole, thiazole, benzothiazole, pyridine,and pyridazine rings are exemplified. A substituted phenyl group(especially p-substituted phenyl group), a substituted or unsubstitutedβ-naphthyl group, or a group derived from a pyridine ring or a thiazolering is especially preferable.

(iii) R₄₁ and R₄₂ are preferably a hydrogen atom, an alkyl group, anaryl group, a heterocyclic group, an acyl group, or an alkyl orarylsulfonyl group, more preferably a hydrogen atom, an alkyl group, anaryl group, or a heterocyclic group, further preferably a hydrogen atom,a substituted aryl group, or a substituted heterocyclic group, and stillfurther preferably a hydrogen atom, or a substituted aryl group.However, both R₄₁ and R₄₂ is not a hydrogen atom at the same time. R₄₃and R₄₁, or R₄₁ and R₄₂ may bond with each other to form a 5- or6-membered ring.

(iv) it is preferable that R₄₃ and R₄₄ each independently represent ahydrogen atom, a halogen atom, an alkyl group, an alkenyl group, analkynyl group, an aralkyl group, an aryl group, a heterocyclic group, acyano group, a carboxyl group, a carbamoyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, a heterocyclic oxycarbonyl group, ahydroxyl group, an amino group which may be an alkylamino group, anarylamino group, or a heterocyclic amino group, an acylamino group, anureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkyl or arylsulfonylamino group, aheterocyclic sulfonylamino group. Further, each of the above groups mayhave a substituent.

R₄₃ is more preferably a hydrogen atom, a halogen atom, an aryl group, aheterocyclic group, a cyano group, a carboxyl group, a carbamoyl group,an alkoxycarbonyl group, an aryloxycarbonyl group, or a heterocyclicoxycarbonyl group, and further preferably a cyano group, a carboxylgroup, a carbamoyl group, or an alkoxycarbonyl group, and still furtherpreferably a cyano group. R₄₄ is more preferably a hydrogen atom, ahalogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaralkyl group, an aryl group, a heterocyclic group, hydroxyl group, anamino group which may be an alkylamino group, an arylamino group, or aheterocyclic amino group, an acylamino group, an ureido group, asulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkyl or arylsulfonylamino group, or aheterocyclic sulfonylamino group, further preferably a hydrogen atom, ahalogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaralkyl group, or an aryl group, and still further preferably a methylgroup.

(v) R₄₅ and R₄₆ are preferably a hydrogen atom, an alkyl group, an arylgroup, a heterocyclic group, an acyl group, or an alkyl or arylsulfonylgroup, more preferably a hydrogen atom, an alkyl group, an aryl group,or a heterocyclic group, further preferably a hydrogen atom, asubstituted aryl group, or a substituted heterocyclic group, and stillfurther preferably a hydrogen atom, or a substituted aryl group.However, both R₄₅ and R₄₆ is not a hydrogen atom at the same time. R₄₅and R₄₆ may bond with each other to form a 5- or 6-membered ring.

As a preferable combination of X₁-X₇, W₁ and R₄₁-R₄₆ in the dyerepresented by formula (B-4), compounds in which at least one of X₁-X₇,W, and R₄₁-R₄₆ is an aforementioned preferable group are preferable, andcompounds in which two or more of X₁-X₇, W, and R₄₁-R₄₆ are each anaforementioned preferable group are more preferable. Compounds in whichall of X₁-X₇, W, and R₄₁-R₄₆ are aforementioned preferable groups aremost preferable.

The formula (B-5) is explained in detail below.

In the formula (B-5), X₁, X₂, X₃, X₄, X₅, X₆, and X₇ each have the samemeanings as X₁, X₂, X₃, X₄, X₅, X₆, and X₇Of the formula (B-3).Preferable examples of X₁, X₂, X₃, X₄, X₅, X₆, and X₇ are also the sameas those of X₁, X₂, X₃, X₄, X₅, X₆, and X₇ of the formula (B-3).

In the formula (B-5), W has the same meaning as W of the formula (B-3).Preferable examples of W are also the same as those of W of the formula(B-3). W₁₁ has the same meaning as W₁ of the formula (B-2). Preferableexamples of W₁₁ are also the same as those of W₁ of the formula (B-2).R₄₁ and R₄₂ each have the same meanings as R₄₁ and R₄₂ of the formula(B-1). Preferable examples of R₄₁ and R₄₂ are also the same as those ofR₄₁ and R₄₂ of the formula (B-1). R₄₃ and R₄₄ each have the samemeanings as R₄₃ and R₄₄ of the formula (B-1). Preferable examples of R₄₃and R₄₄ are also the same as those of R₄₃ and R₄₄ of the formula (B-1).R₄₅ and R₄₆ each have the same meanings as R₄ and R₄₂ of the formula(B-3). Preferable examples of R₄₅ and R₄₆ are also the same as those ofR₄₁ and R₄₂ of the formula (B-3).

As an especially preferable combination of groups in the compoundrepresented by the formula (B-5), combinations composed of the following(i) to (vi) are recited.

(i) X₁, X₂, X₃, X₄, X₅, X₆, and X₇ is a hydrogen atom, a halogen atom,an alkyl group, an aryl group, a heterocyclic group, a cyano group, analkoxy group, an amido group, an ureido group, an alkylsulfonylaminogroup, an arylsulfonylamino group, a sulfamoyl group, an alkylsulfonylgroup, an arylsulfonyl group, a carbamoyl group, an alkoxycarbonylgroup, a sulfo group which may be a salt thereof, a carboxyl group whichmay be a salt thereof, a hydroxyl group which may be a salt thereof, aphosphono group which may be a salt thereof, or a quaternary ammoniumgroup. Further, a hydrogen atom, a halogen atom, an alkyl group, a sulfogroup which may be a salt thereof, a carboxyl group which may be a saltthereof, or a hydroxyl group which may be a salt thereof is morepreferable. Among these groups, a hydrogen atom, a sulfo group which maybe a salt thereof, or a carboxyl group which may be a salt thereof isfurther preferable. It is especially preferable that at least one of X₁,X₂, X₃, X₄, X₅, X₆, and X₇ is a sulfo group which may be a salt thereof,or a carboxyl group which may be a salt thereof.

(ii) W is preferably a substituted phenyl group, a substituted orunsubstituted naphthyl group, or a substituted or unsubstitutedheterocyclic group. As the hetero ring serving as the heterocyclicgroup, pyrrole, thiophene, imidazole, thiazole, benzothiazole, pyridine,and pyridazine rings are exemplified. A substituted phenyl group(especially p-substituted phenyl group), a substituted or unsubstitutedβ-naphthyl group, or a group derived from a pyridine ring or a thiazolering is especially preferable.

(iii) W₁₁ preferably represents an electron withdrawing group having aHammett substituent constant σ p of 0.20 or more, and more preferably0.30 or more, and further preferably 0.45 or more, and still furtherpreferably 0.60 or more. The upper limit of the σ p value is preferably1.0. In more detail, W₁₁ is preferably an acyl group having 2 to 20carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, anitro group, a cyano group, an alkylsulfonyl group having 1 to 20 carbonatoms, an arylsulfonyl group having 6 to 20 carbon atoms, a carbamoylgroup having 1 to 20 carbon atoms, or a halogenated alkyl group having 1to 20 carbon atoms. Among these groups, a cyano group, an alkylsulfonylgroup having 1 to 20 carbon atoms, or an arylsulfonyl group having 6 to20 carbon atoms is more preferable. Especially, a cyano group is mostpreferable.

(iv) R₄₁ and R₄₂ are preferably a hydrogen atom, an alkyl group, an arylgroup, a heterocyclic group, an acyl group, or an alkyl or arylsulfonylgroup, more preferably a hydrogen atom, an alkyl group, an aryl group,or a heterocyclic group, further preferably a hydrogen atom, asubstituted aryl group, or a substituted heterocyclic group, and stillfurther preferably a hydrogen atom, or a substituted aryl group.However, both R₄₁ and R₄₂ is not a hydrogen atom at the same time. R₄₃and R₄₁, or R₄₁ and R₄₂ may bond with each other to form a 5- or6-membered ring.

(v) it is preferable that R₄₃ and R₄₄ each independently represent ahydrogen atom; a halogen atom; an alkyl group; an alkenyl group; analkynyl group; an aralkyl group; an aryl group; a heterocyclic group; acyano group; a carboxyl group; a carbamoyl group; an alkoxycarbonylgroup; an aryloxycarbonyl group; a heterocyclic oxycarbonyl group; ahydroxyl group; an amino group which may be an alkylamino group, anarylamino group, or a heterocyclic amino group; an acylamino group; anureido group; a sulfamoylamino group; an alkoxycarbonylamino group; anaryloxycarbonylamino group; an alkyl or arylsulfonylamino group; or aheterocyclic sulfonylamino group. Further, each of the above groups mayhave a substituent.

R₄₃ is more preferably a hydrogen atom, a halogen atom, an aryl group, aheterocyclic group, a cyano group, a carboxyl group, a carbamoyl group,an alkoxycarbonyl group, an aryloxycarbonyl group, or a heterocyclicoxycarbonyl group, further preferably a cyano group, a carboxyl group, acarbamoyl group, or an alkoxycarbonyl group, and still furtherpreferably a cyano group. R₄₄ is more preferably a hydrogen atom; ahalogen atom; an alkyl group; an alkenyl group; an alkynyl group; anaralkyl group; an aryl group; a heterocyclic group; hydroxyl group; anamino group which may be an alkylamino group, an arylamino group, or aheterocyclic amino group; an acylamino group; an ureido group; asulfamoylamino group; an alkoxycarbonylamino group; anaryloxycarbonylamino group; an alkyl or arylsulfonylamino group; or aheterocyclic sulfonylamino group; further preferably a hydrogen atom, ahalogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaralkyl group, or an aryl group, and still further preferably a methylgroup.

(vi) R₄₅ and R₄₆ are preferably a hydrogen atom, an alkyl group, an arylgroup, a heterocyclic group, an acyl group, or an alkyl or arylsulfonylgroup, more preferably a hydrogen atom, an alkyl group, an aryl group,or a heterocyclic group, further preferably a hydrogen atom, asubstituted aryl group, or a substituted heterocyclic group, and stillfurther preferably a hydrogen atom, or a substituted aryl group.However, both R₄₅ and R₄₆ is not a hydrogen atom at the same time. R₄₅and R₄₆ may bond with each other to form a 5- or 6-membered ring.

As a preferable combination of X₁-X₇, W, W₁, and R₄₁-R₄₆ in the dyerepresented by formula (B-5), compounds in which at least one of X₁-X₇,W, W₁, and R₄₁-R₄₆ is an aforementioned preferable group are preferable,and compounds in which two or more of X₁-X₇, W, W₁, and R₄₁-R₄₆ are eachan aforementioned preferable group are more preferable. Compounds inwhich all of X₁-X₇, W, W₁, and R₄₁-R₄₆ are aforementioned preferablegroups are most preferable.

Of the compound represented by the formula (B-4), or the formula (B-5),compounds represented by the following formula (B-4-1), or formula(B-5-1) are more preferable in that more excellent properties are givenby these compounds in the invention.

In the formula (B-4-1), R₁₁ and R₁₂ each independently represent anionic hydrophilic group. As the ionic hydrophilic group, a sulfo groupwhich may be a salt thereof, and a carboxyl group which may be a saltthereof are especially preferable. Of these groups, a sulfo group ispreferable. m and n each independently represent an integer of 1 to 3,preferably an integer of 1 to 2. It is most preferable that m is 1and/or n is 1. W has the same meaning as W of the formula (B-4).Preferable examples of W are also the same as those of W of the formula(B-4). X₁, X₂, X₃, X₄, X₅, X₆, and X₇ each have the same meanings as X₁,X₂, X₃, X₄, X₅, X₆, and X₇ of the formula (B-4). Preferable examples ofX₁, X₂, X₃, X₄, X₅, X₆, and X₇ are also the same as those of X₁, X₂, X₃,X₄, X₅, X₆, and X₇ of the formula (B-4).

In the formula (B-5-1), R₁₁ and R₁₂ each independently represent anionic hydrophilic group. As the ionic hydrophilic group, a sulfo groupwhich may be a salt thereof and a carboxyl group which may be a saltthereof are especially preferable. Of these groups, a sulfo group ispreferable. m and n each independently represent an integer of 1 to 3,preferably an integer of 1 to 2. It is most preferable that m is 1and/or n is 1. W has the same meaning as W of the formula (B-5).Preferable examples of W are also the same as those of W of the formula(B-5). W₁₁ has the same meaning as W₁₁ of the formula (B-5). Preferableexamples of W₁₁ are also the same as those of W₁₁ of the formula (B-5).X₁, X₂, X₃, X₄, X₅, X₆, and X₇ each have the same meanings as X₁, X₂,X₃, X₄, X₅, X₆, and X₇ of the formula (B-5). Preferable examples of X₁,X₂, X₃, X₄, X₅, X₆, and X₇ are also the same as those of X₁, X₂, X₃, X₄,X₅, X₆, and X₇Of the formula (B-5).

In the black ink used in the invention, other black dyes may be used incombination with the compound represented by any one of theabove-described formulae (B-1) to (B-5-1). The other black dye is notparticularly limited, but known dyes may be optionally and selectivelyused.

Preparation methods of various kinds of inks are minutely described inJP-A-Nos. 5-148436, 5-295312, 7-97541, 7-82515, and 7-118584, and theymay be applied to the preparation of inkjet recording inks used in theinvention.

<Inkjet Recording Method>

The inkjet recording method of the invention includes a process ofrecording an image on an inkjet recording medium having an ink-receivinglayer containing inorganic fine particles on a support, using theabove-described inkjet recording yellow ink of the invention, or theabove-described inkjet recording ink set of the invention.

In the inkjet recording method of the invention, an image is recordedwith the inkjet recording yellow ink of the invention as a yellow ink.Therefore, when the recorded image is stored for a long period of time,a substantial change of color balance of the image can be supressed. Asa result, it is possible to obtain an image in which stability of colortone has been maintained over a long period of time.

As the material to be recorded by using the ink set of the invention, itis possible to use materials known to be applied for recording, such asa recording paper, a resin coat paper, an inkjet exclusive paper asdescribed in, for example, JP-A-Nos. 8-169172, 8-27693, 2-276670,7-276789, 9-323475, 62-238783, 10-153989, 10-217473, 10-235995,10-337947, 10-217597, and 10-337947, a film, a paper for common use ininkjet recording and electrophotographic transfer, a textile, a glass, ametal, or ceramics.

An example of the support is a paper manufactured from chemical pulpsuch as LBKP or NBKP, mechanical pulp such as GP, PGW, RMP, TMP, CTMP,CMP or CGP, or waste paper pulp such as DIP, wherein known additivesincluding a dye, a binder, a sizing agent, a fixing agent, a cationicagent and a paper strength increasing agent are mixed as needed, by useof a paper machine such as a Fourdrinier machine or a vat machine. Otherexamples of the support are synthetic paper and plastic film sheets. Thesuitable thickness of the support is from 10 to 250 μm, and the suitablebasis weight of the support is from 10 to 250 g/m².

As the support, a paper laminated with polyolefin (e.g., polyethylene,styrene, polybutene, and copolymers thereof) or polyethyleneterephthalate on both sides, or plastic film is more preferably used. Tothe polyolefin, a white pigment (e.g., titanium dioxide, zinc oxide) ora tinting dye (e.g., cobalt blue, ultramarine blue, neodymium oxide) ispreferably added.

In the invention, it is preferable that an inkjet recording medium hasan ink-receiving layer containing inorganic fine particles on thesupport. The ink-receiving layer provided on the support is explainedbelow.

In the image-receiving layer, a porous material and an aqueous bindermay be incorporated as a component. Further, as the inorganic fineparticles, a pigment is preferably contained in the image-receivinglayer. A white pigment is suitable as the pigment. Examples of a whitepigment include inorganic white pigments, such as calcium carbonate,kaolin, talc, clay, diatomaceous earth, synthetic amorphous silica,aluminum silicate, magnesium silicate, calcium silicate, aluminumhydroxide, alumina, lithopone, zeolite, barium sulfate, calcium sulfate,titanium dioxide, zinc sulfide and zinc carbonate; and organic pigments,such as styrene pigment, acrylic pigment, urethane resin and melamineresin. Of these pigments, porous white inorganic pigments are preferredover the others. Particularly, synthetic amorphous silica having a greatpore area is preferably used. As the synthetic amorphous silica, silicicacid anhydride synthesized in dry process (vapor-phase process), orhydrated silicic acid synthesized in a wet process is usable.

Examples of the inkjet recording medium containing the foregoingpigments in its image-receiving layer include those disclosed inJP-A-Nos. 10-81064, 10-119423, 10-157277, 10-217601, 11-348409,2001-138621, 2000-43401, 2000-211235, 2000-309157, 2001-96897,2001-138627, 11-91242, 8-2087, 8-2090, 8-2091, 8-2093, 8-174992,11-192777 and 2001-301314.

Examples of an aqueous binder contained in the image-receiving layerinclude water-soluble polymers, such as polyvinyl alcohol or polyvinylalcohol derivatives, for example, polyvinyl alcohol and silanol-modifiedpolyvinyl alcohol; starch, cationic starch, casein, gelatin,carboxymethyl cellulose, hydroxyethyl cellulsode, polyvinyl pyrrolidone,polyalkylene oxides and polyalkylene oxide derivatives; andwater-dispersible polymers, such as styrene-butadiene latex and anacrylic emulsion. These aqueous binders can be used alone or ascombinations of two or more thereof. Of those aqueous binders, polyvinylalcohol or polyvinyl alcohol derivatives such as polyvinyl alcohol andsilanol-modified polyvinyl alcohol are especially favorable from theviewpoints of adhesion to pigments and delamination resistance of theink-receiving layer.

In addition to pigments and aqueous binders, the image-receiving layermay further contain other additives, such as a mordant, a waterproofingagent, a light resistance improver, a gas resistance improver, asurfactant and a hardener. To the image-receiving layer, an immobilizedmordant is preferably added. Therefore, it is appropriate to use apolymeric mordant from a viewpoint of bleeding prevention.

The method of jetting ink that is used in the inkjet recording ink setof the invention is not particularly restricted, but any known methodsmay be used. More specifically, methods usable in the invention includea charge control method in which ink is jetted by utilizing an inducedelectrostatic force, a drop-on-demand method (a pressure pulse method)utilizing piezo element vibration pressure, an acoustic inkjet method inwhich radiation pressure created by irradiating ink with acoustic beamsconverted from electric signals is utilized for jetting ink, and athermal inkjet (Bubble Jet, Registered Trademark) method in whichbubbles are formed by heating ink and the pressure created thereby isutilized for jetting ink. The inkjet recording methods included a methodof jetting a great number of minute-volume droplets of ink low indensity referred to as the photo ink, a method of improving imagequality by the use of two or more kinds of ink substantially the same inhue but different in density, and a method of using colorless invisibleink.

EXAMPLES

The invention will be described below in more detail with reference toexamples therefor. The invention is not limited to below-describedexamples, provided that no departure is made from the essence thereof.Further, the term “part” is based on a weight standard, unless statedotherwise.

Example 1 Preparation of Ink Set (Preparation of Yellow Ink Y-101)

To the following ingredients, ion-exchange water was added in an amountto make the total weight 1000 g, and stirred for 1 hour while heating ata temperature of 30 to 40° C. The resulting solution was passed througha vacuum microfilter 0.2 μm in average pore diameter, thereby preparinga yellow ink Y-101.

<Formula of Yellow ink Y-101> -Solid Components- Potassium salt ofYellow dye Y-1 set forth below 60.0 g PROXEL XL-2 1.0 g(1,2-dibezisothiazoline-3-on manufactured by Arch Chemicals Japan, Inc.)-Liquid Components- Glycerin 20 g Ethylene glycol mono butyl ether (HLBvalue =7.33) 250 g OLFINE E1010 20 g (Ethylene oxide (10 mol) adduct ofacetylene diol (nonionic surfactant) manufactured by Nissin ChemicalIndustry Co, Ltd.) Ion exchange water 649 g (Amount to make the totalweight 1000 g) Yellow Dye Y-1

(Preparation of Magenta Ink M-101)

To the following ingredients, ion-exchange water was added in an amountto make the total weight 1000 g, and stirred for 1 hour while heating ata temperature of 30 to 40° C. The resulting solution was passed througha vacuum microfilter 0.2 μm in average pore diameter, thereby preparinga magenta ink M-101.

<Formula of Magenta ink M-101> -Solid Components- Magenta dye M-1 setforth below 30.0 g Urea 48.0 g PROXEL XL-2 1.0 g (Product manufacturedby Arch Chemicals Japan, Inc.) -Liquid Components- Glycerin 84.0 gTriethylene glycol 20.0 g Triethylene glycol mono butyl ether 99.0 gPropylene glycol 3.0 g Betaine compound W-1 set forth below 17.0 g Ionexchange water 698 g (Amount to make the total weight 1000 g) MagentaDye M-1

Betaine Compound W-1

(Preparation of Cyan Ink C-101)

To the following ingredients, ion-exchange water was added in an amountto make the total weight 1000 g, and stirred for 1 hour while heating ata temperature of 30 to 40° C. The resulting solution was passed througha vacuum microfilter 0.2 μm in average pore diameter, thereby preparinga cyan ink C-101.

<Formula of Cyan ink C-101> -Solid Components- Cyan dye C-1 set forthbelow 54.0 g Aminoguanidine hydrochloride 20.0 g Urea 35.0 g Bronzeimproving agent A set forth below 10.0 g PROXEL XL-2 1.0 g (Productmanufactured by Arch Chemicals Japan, Inc.) -Liquid Components- Glycerin90 g Triethylene glycol 20 g Triethylene glycol mono butyl ether 94 gPropylene glycol 3 g 1,2-Hexanediol 12 g 2-Pyrrolidone 30 g OLFINE E101010 g (Ethylene oxide (10 mol) adduct of acetylene diol (nonionicsurfactant) manufactured by Nissin Chemical Industry Co, Ltd.) Ionexchange water 621 g (Amount to make the total weight 1000 g) Cyan dyeC-1

One of Rings A to D

The other three

The mark * indicates a bond site of the phthalocyanine ring. Bronzeimproving agent

(Preparation of Black Ink Bk-101)

To the following ingredients, ion-exchange water was added in an amountto make the total weight 1000 g, and stirred for 1 hour while heating ata temperature of 30 to 40° C. The resulting solution was passed througha vacuum microfilter 0.2 μm in average pore diameter, thereby preparinga black ink Bk-101.

<Formula of Black ink Bk-101> -Solid Components- Black dye 1 (primaryblack dye Bk-1 set forth below) 62.0 g Black dye 2 (complementary blackdye Bk-2 set forth below) 10.0 g PROXEL XL-2 1.0 g (Product manufacturedby Arch Chemicals Japan, Inc.) -Liquid Components- Glycerin 80 gTriethylene glycol 10 g Triethylene glycol mono butyl ether 85 gPropylene glycol 3 g 1,2-Hexanediol 16 g OLFINE E1010 10 g (Ethyleneoxide (10 mol) adduct of acetylene diol (nonionic surfactant)manufactured by Nissin Chemical Industry Co, Ltd.) Ion exchange water723 g (Amount to make the total weight 1000 g) Primary black dye Bk-1

Complementary black dye Bk-2

(Preparation of Ink Set 1)

The ink set 1 composed of the above-obtained Yellow ink Y-101, Magentaink M-101, Cyan ink C-101, and Black ink Bk-101 was prepared.

<Preparation of Ink Sets 2 to 18>

(Preparation of Yellow inks Y-102 to Y-118)

Yellow inks Y-102 to Y-118 were prepared in the same manner as theabove-described yellow inks Y-101 respectively, except that theadditives of the yellow ink Y-101 were changed to those materials setforth in Tables 1 to 3.

TABLE 1 Material Y-101 Y102 Y103 Y104 Y-105 Y-106 Yellow dye Y-1 60 6048 48 Yellow dye Y-2 60 50 PRO-JET Yellow-1 12 10 PRO-JET Yellow-1G 12Urea 40 Glycerin 20 40 30 20 40 20 EGmBE (7.33) 250 230 EGmPE (7.81) 200EGmEE (8.28) 250 EGmME (8.76) 230 DEGmBE (7.66) 250 PROXEL XL-2 1 1 1 11 1 OLFINE E1010 20 20 20 20 20 20 Ion exchange water RemainderRemainder Remainder Remainder Remainder Remainder Total amount 1000 g1000 g 1000 g 1000 g 1000 g 1000 g

TABLE 2 Material Y-107 Y108 Y109 Y110 Y-111 Y-112 Yellow dye Y-1 60 5060 60 60 Yellow dye Y-2 60 PRO-JET Yellow-1 10 Urea 40 Glycerin 60 20 2020 20 20 DEGmPE (8.14) 110 DEGmEE (8.61) 100 200 DEGmME (9.09) 150 PGmEE(7.80) 150 PGmME (8.28) 100 DPGmEE (7.65) 210 DPGmEE (8.13) 250 TEGmBE(7.99) 50 TEG 100 PROXEL XL-2 1 1 1 1 1 1 OLFINE E1010 20 20 20 20 20 20Ion exchange water Remainder Remainder Remainder Remainder RemainderRemainder Total amount 1000 g 1000 g 1000 g 1000 g 1000 g 1000 g

TABLE 3 Material Y-113 Y114 Y115 Y116 Y-117 Y-118 Yellow dye Y-1 60 6060 60 60 60 Glycerin 40 20 20 80 30 20 EGmEE (8.28) 76 DEGmME (9.09) 60TEGmBE (7.99) 50 190 250 90 130 DPGmBE (6.70) 240 120 TEG 64 96 PG 40 44 PROXEL XL-2 1 1 1 1 1 1 OLFINE E1010 20 20 20 20 20 20 Ion exchangewater Remainder Remainder Remainder Remainder Remainder Remainder Totalamount 1000 g 1000 g 1000 g 1000 g 1000 g 1000 g

Details of the abbreviations described in the above Tables 1 to 3 are asfollows. In the Tables 1 to 3, numerical values in parenthesis indicateHLB values calculated by the Davis method.

EGmBE: Ethylene glycol monobutyl etherEGmPE: Ethylene glycol monopropyl etherEGmEE: Ethylene glycol monoethyl etherEGmME: Ethylene glycol monomethyl etherDEGmBE: Diethylene glycol monobutyl etherDEGmPE: Diethylene glycol monopropyl etherDEGmEE: Diethylene glycol monoethyl etherDEGmME: Diethylene glycol monomethyl etherPGmEE: Propylene glycol monoethyl etherPGmME: Propylene glycol monomethyl etherDPmEE: Dipropylene glycol monoethyl etherDPmME: Dipropylene glycol monomethyl etherTEGmBE: Triethylene glycol monobutyl etherDPGmBE: Dipropylene glycol monobutyl etherTEG: Triethylene glycolPG: Propylene glycol

PRO-JET Yellow −1: a 7.5% aqueous solution of Direct Yellow 86(Product manufactured by FUJIFILM Imaging Colorants Co., Ltd.)PRO-JET Yellow −1G: a 7.5% aqueous solution of Direct Yellow 132(Product manufactured by FUJIFILM Imaging Colorants Co., Ltd.)

(Preparation of Ink Sets 2 to 18)

Ink sets 2 to 18 were prepared in the same manner as the ink set 1respectively, except that the yellow ink Y-101 was replaced by Y-102 toY-118.

<Image Recording and Evaluation>

Each of the thus-obtained ink sets 1 to 18 was loaded respectively in aDry Minilab 400 ink cartridge manufactured by FUJIFILM Corporation.Recording was performed on an ink jet image-receiving paper “KASSAI”roll paper manufactured by FUJIFILM Corporation under the conditions of23° C. and 50% RH. Samples of each of yellow, magenta and cyan having amonochromatic density different from each other were prepared. Further,samples each having a different image density of three color compositegray consisting of yellow, magenta and cyan were also prepared. Then,the following image evaluation was performed.

Ozone Resistance

The image density Ci of each of yellow, magenta and cyan was measuredusing an X-rite 310 in accordance with “Digital Color Photo PrintStability Evaluation” as defined by JEITA CP-3901 (Japan Electronics andInformation Technology Industries Association standard). With respect tothe composite neutral patch, the monochrome patch and the background,patches corresponding to the following density ranges were selected.

BACKGROUND Density 0.5 Patch 0.5±10% Density 1.0 Patch 1.0±10% Density1.5 Patch 1.5±10%

Next, these patches were allowed to stand in a box having a fixed ozonegas density of 5 p p m. Image densities of the patches before and afterstanding under the ozone gas atmosphere were measured using a reflectiondensitometer (X-rite 310 TR) to obtain a residual ratio of the dye (%,=Cf/Ci×100). The lifetime of each image was evaluated on the basis ofnumerical data obtained by both individual color monochromatic patchesand composite neutral patches in terms of the residual ratio of the dyeaccording to JEITA CP-3901. The evaluation results are shown in Table 4set forth below. Herein, the number of lifetime years is determined onthe basis of color variation, color balance variation and reflectiondensity of the background with respect to each of the colorants in theimage.

TABLE 4 Lifetime Content of according to Glycol JEITA Ink Set Yellow Inkether (*1) CP-3901 (years) Note 1 Y-101 92.6% 11.3 Invention 2 Y-10285.2% 11.2 Invention 3 Y-103 87.0% 10.8 Invention 4 Y-104 92.6% 12.1Invention 5 Y-105 85.2% 11.9 Invention 6 Y-106 92.6% 11.1 Invention 7Y-107 77.8% 12.5 Invention 8 Y-108 55.6% 12.3 Invention 9 Y-109 92.6%11.3 Invention 10 Y-110 91.3% 11.0 Invention 11 Y-111 92.6% 12.5Invention 12 Y-112 74.1% 11.5 Invention 13 Y-113 28.1% 11.2 Invention 14Y-114 22.2% 9.6 Comp. Ex. *2 15 Y-115 — 8.3 Comp. Ex. *2 16 Y-116 — 8.1Comp. Ex. *2 17 Y-117 — 7.9 Comp. Ex. *2 18 Y-118 — 8.2 Comp. Ex. *2(*1): A content (mass %) that the glycol ether represented by formula(A) occupies with the entire water-soluble organic solvent *2:Abbreviation of Comparative Example

As shown in the above Table 4, in the yellow inks of the invention, adeterioration of color balance owing to ozone fading with a lapse oftime after recording of an image is reduced, thereby improving alifetime of the recorded image, which results in improvement of thestorage stability over a long period of time.

1. An inkjet recording yellow ink comprising at least one water-solubleazo dye selected from the group consisting of a compound represented byformula (Y) described below and a salt thereof and at least one glycolether represented by formula (A) described below, wherein the glycolether is contained in an amount of 25% by mass to 100% by mass relativeto a total amount of water-soluble organic solvent in the ink:

wherein in formula (Y), G represents a heterocyclic group; R, X, Y, Z,and Q each independently represent a monovalent, divalent, or trivalentgroup; n represents an integer of 1 to 3; when n is 1, R, X, Y, Z, Q andG each independently represent a monovalent group; when n is 2, R, X, Y,Z, Q and G each independently represent a monovalent or divalent group,and at least one of them represents a divalent substituent; and when nis 3, R, X, Y, Z, Q and G each independently represent a monovalent,divalent, or trivalent group, and at least two of them represent adivalent substituent, or at least one of them represents a trivalentsubstituent:

wherein in formula (A), A represents an ethyleneoxy group or apropyleneoxy group; when A represents an ethyleneoxy group, R representsa straight chain alkyl group having 1 to 4 carbon atoms; when Arepresents a propyleneoxy group, R represents a straight chain alkylgroup having 1 to 2 carbon atoms; and n represents 1 or
 2. 2. The inkjetrecording yellow ink described in claim 1, wherein the glycol ether hasan HLB value by the Davis method of 7.0 to 9.5.
 3. The inkjet recordingyellow ink described in claim 1, wherein the compound represented byformula (Y) is selected from the group consisting of a compoundrepresented by formula (Y-1) described below, a compound represented byformula (Y-2) described below, a compound represented by formula (Y-3)described below, a compound represented by formula (Y-4) describedbelow, a compound represented by formula (Y-5) described below, and asalt of any one of these compounds:

wherein in formula (Y-1), R₁, R₂, X₁, X₂, Y₁, Y₂, Z₁, and Z₂ eachindependently represent a monovalent group; G represents an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring; Mrepresents a hydrogen atom or a cation; and m₁ represents an integer of0 to 3,

wherein in formula (Y-2), R₁, R₂, R₁₁, R₁₂, X₁, X₂, Z₁, and Z₂ eachindependently represent a monovalent group; L₁ represents a divalentconnecting group; G₁ and G₂ each independently represent an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring; Mrepresents a hydrogen atom or a cation; and m₂₁ and m₂₂ eachindependently represent an integer of 0 to 3,

wherein in formula (Y-3), R₁, R₂, R₁₁, R₁₂, X₁, X₂, Y₁, and Y₂ eachindependently represent a monovalent group; L₂ represents a divalentconnecting group; G₁ and G₂ each independently represent an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring; Mrepresents a hydrogen atom or a cation; and m₃₁ and m₃₂ eachindependently represent an integer of 0 to 3,

wherein in formula (Y-4), R₁₁, R₁₂, X₁, X₂, Y₁, Y₂, Z₁, and Z₂ eachindependently represent a monovalent group; L₃ represents a divalentconnecting group; G₁ and G₂ each independently represent an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring; Mrepresents a hydrogen atom or a cation; and m₄₁ and M₄₂ eachindependently represent an integer of 0 to 3,

wherein, in formula (Y-5), R₁, R₂, R₁₁, R₁₂, Y₁, Y₂, Z₁, and Z₂ eachindependently represent a monovalent group; L₄ represents a divalentconnecting group; G₁ and G₂ each independently represent an atomic groupnecessary to form a 5- to 8-membered nitrogen-containing hetero ring; Mrepresents a hydrogen atom or a cation; and m₅₁ and m₅₂ eachindependently represent an integer of 0 to
 3. 4. The inkjet recordingyellow ink described in claim 1, wherein the glycol ether has an HLBvalue by the Davis method of 8.1 to 9.1.
 5. The inkjet recording yellowink described in claim 1, wherein the glycol ether is at least onecompound selected from the group consisting of diethylene glycolmonopropylether, diethylene glycol monoethylether, ethylene glycolmonoethylether, diethylene glycol monomethylether, ethylene glycolmonomethylether, dipropylene glycol monomethylether, and propyleneglycol monomethylether.
 6. The inkjet recording yellow ink described inclaim 1, further comprising a nonionic surfactant.
 7. The inkjetrecording yellow ink described in claim 6, wherein the nonionicsurfactant is an acetylene diol-series nonionic surfactant.
 8. An inkjetrecording ink set comprising the inkjet recording yellow ink describedin claim 1, a magenta ink containing a magenta dye, and a cyan inkcontaining a cyan dye.
 9. The inkjet recording ink set described inclaim 8, wherein the cyan dye is a water-soluble phthalocyanine dyeselected from the group consisting of a compound represented by formula(C-1) described below and a salt thereof:

wherein, in formula (C-1), Q₁ to Q₄, P₁ to P₄, W₁ to W₄, and R₁ to R₄each independently represent (═C(J₁)- or —N═), (═C(J₂)- or —N═),(═C(J₃)- or —N═), or (═C(J₄)- or —N═); J₁ to J₄ each independentlyrepresent a hydrogen atom or a substituent; the four rings of ring Acomprising “Q₁, P₁, W₁ and R₁”, the ring B comprising “Q₂, P₂, W₂ andR₂”, the ring C comprising “Q₃, P₃, W₃ and R₃”, and the ring Dcomprising “Q₄, P₄, W₄ and R₄” each independently represent an aromatichydrocarbon ring or a hetero ring; and M represents a hydrogen atom, ametal element, a metal oxide, a metal hydroxide, or a metal halide. 10.The inkjet recording ink set described in claim 8, wherein the magentaink contains a water-soluble azo dye represented by formula (M-1)described below:

wherein in formula (M-1), A represents a residue of a 5-membered heteroring diazo component A-NH₂; B₁ and B₂ each independently represent—CR₁₃═ or —CR₁₄═, or alternatively one of B₁ and B₂ is a nitrogen atom,and the other is —CR₁₃═, or —CR₁₄═; R₁₁ and R₁₂ each independentlyrepresent a hydrogen atom, an alkyl group, a cycloalkyl group, analkenyl group, an alkynyl group, an aralkyl group, an aryl group, aheterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group; G, R₁₃, and R₁₄ eachindependently represent a hydrogen atom, a halogen atom, an alkyl group,an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, aheterocyclic group, a cyano group, a carboxyl group, a carbamoyl group,an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, ahydroxyl group, an alkoxy group, an aryloxy group, a silyloxy group, anacyloxy group, a carbamoyloxy group, a heterocyclic oxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino groupsubstituted with an alkyl group, an aryl group, or a heterocyclic group,an acylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, analkylsulfonylamino group, an arylsulfonylamino group, a nitro group, analkylthio group, an arylthio group, an alkylsulfonyl group, anarylsulfonyl group, an alkyl sulfinyl group, an arylsulfinyl group, asulfamoyl group, a heterocyclic thio group, or an ionic hydrophilicgroup; R₁₃ and R₁₁, or R₁₁ and R₁₂ may bond with each other to form a 5-or 6-membered ring; and the formula (M-1) must have at least one ionichydrophilic group.
 11. The inkjet recording ink set described in claim8, further comprising a black ink.
 12. The inkjet recording ink setdescribed in claim 11, wherein the black ink contains a water-solubleazo dye represented by formula (B-1) described below:

wherein in formula (B-1), A represents a monovalent aromatic group orheterocyclic group; B represents a divalent aromatic group orheterocyclic group; T₁ and T₂ each independently represent ═CR₄₃— or—CR₄₄═, or alternatively, one of T₁ and T₂ is a nitrogen atom, and theother is ═CR₄₃— or —CR₄₄═; V₁, R₄₃ and R₄₄ each independently representa hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, analkynyl group, an aralkyl group, an aryl group, a heterocyclic group, acyano group, a carboxyl group, a carbamoyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, a heterocyclic oxycarbonyl group, anacyl group, a hydroxyl group, an alkoxy group, an aryloxy group, aheterocyclic oxy group, a silyloxy group, an acyloxy group, acarbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxygroup, an amino group which may be an alkylamino group, an arylaminogroup, or a heterocyclic amino group, an acylamino group, a ureidogroup, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group, or a sulfo group; R₄₁ and R₄₂ eachindependently represent a hydrogen atom, an alkyl group, an alkenylgroup, an alkynyl group, an aralkyl group, an aryl group, a heterocyclicgroup, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or asulfamoyl group, with the proviso that both R₄₁ and R₄₂ are not ahydrogen atom at the same time; and R₄₃ and R₄₁, or R₄₁ and R₄₂ may bondwith each other to form a 5- or 6-membered ring.
 13. A inkjet recordingmethod for recording an image on an inkjet recording medium having anink-receiving layer containing inorganic fine particles on a support,the method comprising: using the inkjet recording yellow ink describedin claim 1, or the inkjet recording ink set described in claim
 8. 14.The inkjet recording method described in claim 13, wherein the inkreceiving layer contains polyvinyl alcohol or a derivative thereof as abinder.